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Students can Download Chapter 5 Magnetism and Matter Questions and Answers, Plus Two Physics Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus Two Physics Chapter Wise Questions and Answers Chapter 5 Magnetism and Matter

Plus Two Physics Magnetism and Matter NCERT Text Book Questions and Answers

Question 1.
Answer the following questions regarding earth’s magnetism:

1. A vector needs three quantities for its specification. Name the three independent quantities conventionally used to specify the earth’s magnetic field.
2. The angle of dip at a location in southern India is about 18°. Would you expect a greater or lesser dip angle in Britain?
3. If you make a map of magnetic field lines at Melbourne in Australia, would the lines seen to go into the ground or come out of the ground?
4. In which direction would a compass free to move in the vertical plane point to, if located right on the geomagnetic north or south pole?
5. The earth’s field is claimed roughly approximately, the field due to a dipole magnetic moment 8 × 10²² JT^-1 located at the centre. Check your or¬der of magnitude of this number same way.
6. Geologists claim that besides the main magnetic NS poles, there are several local poles on the earth’s surface oriented in different directions. How is such a thing possible at all?

Answer:
1. Magnetic declination, angle of dip, horizontal component of earth’s magnetic field.

2. Greater angle of dip in Britain, (it is about 70°), because Britain is closer to the magnetic north pole.

3. Field lines of B due to the earth’s magnetism would seem to come out of the ground.

4. A compass is free to move in a horizontal plane, while the earth’s field is exactly vertical at the magnetic poles. So the compass can point in any direction there.

5. Use the formula for field B on the normal bisector of a dipole of magnetic moment m.
B = \(\frac{\mu_{0}}{4 \pi} \frac{M}{r^{3}}\)
Take M = 8 × 10²² JT^-1
r = 6.4 × 10⁶ m;
one gets B = 0.3G
which checks with the orde of magnitude of the observed field on the earth.

6. The earth’s field is only approximately a dipole field. Local N-S poles may arise due to, for instance, magnetized minerals deposits.

Question 2.
A short bar magnet of magnetic moment m = 0.32JT^-1 is placed in a uniform external magnetic field of 0.15T. If the bar is free to rotate in the plane of the field, which orientations would correspond to its

• stable and
• unstable equilibrium? What is the potential energy of the magnet in each case?

Answer:
Given M=0.32JT^-1 B = 0.15T, U = ?

• If \(\overrightarrow{\mathrm{M}} \| \overrightarrow{\mathrm{B}}\), then we have stable equilibrium and U = -MB = -0.32 × 0.15T = -4.8 × 10^-2 J
• If \(\overrightarrow{\mathrm{M}}\) is anti-parallel to \(\overrightarrow{\mathrm{B}}\) , we have unstable equilibrium and
  U = MB = 0.32 × 0.15J = 4.8 × 10^-2J

Question 3.
A closely wound solenoid of 800 turns and area of cross-section 2.5 × 10^-4 m² carries a current of 3.0A. Explain the sense in which the solenoid acts like a bar magnet. What is its associated magnetic moment?
Answer:
Given N = 800, A = 2.5 × 10^-4 m², I = 3.0A, M = ?
Since M = NIA
∴ M = 800 × 3 × 2.5 × 10^-4
or M = 0.60JT^-1 along the axis of the solenoid.

Question 4.
A closely wound solenoid of 2000 turns and area of cross-section 1.6 × 10^-4 m², carrying a current of 4.0A, is suspended through its centre allowing it to turn in a horizontal plane.

1. What is the magnetic moment associated with the solenoid?
2. What is the force and torque on the solenoid if a uniform horizontal magnetic field of 7.5 × 10^-2 is set up at an angle of 30° with the axis of the sole¬noid?

Answer:
1. Magnetic dipole moment,
M = nIA
= 2000 × 4.0 × 1.6 × 10^-4 = 1.28JT^-1

2. Net force = 0
Torque, τ = MB sinθ
= 1.28 × 7.5 × 10^-2 × sin 30°
= 1.28 × 7.5 × 10^-3 × 1/2 = 4.8 × 10^-2 Nm.

Question 5.
Answer the following questions:

1. Why does a paramagnetic sample display greater magnetization (for the same magnetizing field) when cooled?
2. Why is diamagnetism, in contrast, almost independent of temperature?
3. If a toroid used bismuth for its core, will the field in the core be (slightly) greater or (slightly) less than when the core is empty?
4.  If the permeability of a ferromagnetic material independent of the magnetic field? If not is it more for lower or higher fields?
5. Magnetic field lines are always nearly normal to the surface of a ferromagnet at every point.
6. Would the maximum possible magnetisation of a paramagnetic sample be of the same order of magnitude as the magnetisation of a ferromagnet?

Answer:
1. The tendency to disrupt the alignment of dipoles (with the magnetising field) arising from random thermal motion is reduced at lower temperatures.

2. The induced dipole moment in a diamagnetic sample is always opposite to the magnetising field, no matter what the internal motion of the atom is.

3. Slightly less, since bismuth is diamagnetic.

4. No, as is evident from the magnetisation curve. From the slope of the magnetisation curve, it is clear that μ is greater for lower fields.

5. Proof of the important fact (of much practical use) is based on boundary conditions of magnetic fields (B & H) at the interface of two media. (When one of the media has μ>>1, the field lines meet this medium nearly normally).

6. Yes. Apart from minor differences in the strength of the individual atomic dipoles of two different materials, a paramagnetic sample with saturated magnetisation will have the same order of magnetisation. But of course, saturation requires impractically high magnetising fields.

Plus Two Physics Magnetism and Matter One Mark Questions and Answers

Question 1.
Nickel shows ferromagnetic property at room temperature. If the temperature is increased beyond Curie temperature, then it will show
(a) anti ferromagnetism
(b) no magnetic property
(c) diamagnetism
(d) paramagnetism
Answer:
(d) paramagnetism

Question 2.
According to Curie’s law, the magnetic susceptibility of a substance at an absolute temperature T is proportional to
(a) 1/T
(b) T
(c) 1/T²
(d) T²
Answer:
(a) 1/T
Explanation : According to Curie’s law X ∝ \(\frac{1}{T}\)

Question 3.
Above Curie temperature
(a) a paramagnetic substance becomes ferromagnetic substance
(b) a ferromagnetic substance becomes paramagnetic
(c) a paramagnetic substance becomes diamagnetic
(d) a diamagnetic substance becomes paramagnetic
Answer:
(b) a ferromagnetic substance becomes paramagnetic

Plus Two Physics Magnetism and Matter Two Mark Questions and Answers

Question 1.
Classify the following properties into diamagnetic, paramagnetic and ferromagnetic.

1. Susceptibility -1≤x<0
2. In uniform magnetic field it acquires a large magnetisation in the direction of the field.
3. When it is suspended in a magnetic field, it will come to rest perpendiculartothe magnetic field.
4. Susceptibility of the substance varies inversely as temperature of the substance upto curie temperature ie. x_m∝ \(\frac{1}{T}\)

Answer:

• Dia – a,c
• Para – d
• Ferro – b

Question 2.
Classify the following properties into diamagnetism and ferro magnetism.

1. In non uniform magnetic field, it more from high to law field.
2. Magnetic field lines are repelled from this material, If we place in a external magnetic field.
3. susceptibility greater than one, <0, +ve
4. Iron, Nickel, Cobalt are the examples

Answer:

1. Diamagnetism
2. Diamagnetism
3. Ferro magnetism
4. Ferro magnetism

Question 3.
Fill in the blanks.

Answer:

1. negative
2. Weak magnetic field to strong magnetic field.
3. Individual atoms have tiny magnetic moments
4. µ_r >1

Plus Two Physics Magnetism and Matter Three Mark Questions and Answers

Question 1.
The figure shows hysteresis curves for soft iron and stell.

1. Which among the two is the hysteresis loop of soft iron?
2. Which one among the two materials is preferred for use in transformers and galvanometers?
3. When steel is once magnetized, the magnetiza-tion is not easily destroyed even if it is exposed to strong reverse fields. Give reason.

Answer:

1. Fig. b
2. Soft iron
3. When steel is magnetised the magnetic domains in the material is permanently set and magnetised permanently in the direction of the applied magnetic field.

Question 2.
The figure shows a liquid placed on the pole pieces of two magnets.

1. Which magnetic behaviour is exhibited by the liquid? (1)
2. Write any two characteristics of this magnetic behaviour? (1)
3. Does this behaviour transform with temperature. Why? (1)

Answer:
1. Diamagnetism
2. characteristics of this magnetic behaviour:

• Permeability of a diamagnetic material is less than one.
• Susceptibility is small and negative.

3. No. The magnetic dipole moment induced in the diamagnetic material is opposite to the magnetising field and hence does not affect the thermal motion of atoms. Hence change in temperature has no effect on diamagnetism.

Question 3.
A magnetic material contained in a curved glass plate, when placed in a nonuniform magnetic field, exhibits a property as shown in figure.

1. Which type of magnetic material is this? Explain the property
2. Write two examples for such a magnetic material. Explain how the property relates with temperature?
3. “The susceptibility of a material is small” what do you mean by this statement.

Answer:

1. Diamagnetism: Diamagnetic materials are repelled from external magnetic field.
2. Bismuth, Copper, Lead, Nitrogen, Water. Diamagnetism is independent of temperature.
3. Diamagnetism developed by external magnetic field is very small.

Question 4.
A place where dip = 90°, B_H = 0

1. This place is at…………
2. What is the value of B_u at this place?
3. Can a magnetic needle align in the N-S direction at this place?

Answer:
1. Magnetic pole.

2. B = \(\sqrt{B_{v}^{2}+B_{h}^{2}}\)
But B_h = 0
∴ B = B_v

3. No. Magnetic needle align vertically

Question 5.
Classify into diamagnet, Paramagnet and Fero magnet.

1. Feebly magnetized in the same direction
2. m_r slightly more than none
3. does not allow lines of force
4. temperature independent
5. exhibit hysteresis
6. strongly attracted by a bar magnet

Answer:

1. Paramagnet
2. Para magnet
3. Dia magnet
4. Diamagnet
5. Ferromagnet
6. Ferromagnet

Plus Two Physics Magnetism and Matter Four Mark Questions and Answers

Question 1.
Magnetic field lines are the visualization of magnetic field.

1. Write any three properties of magnetic field lines.
2. The arrangement shows two bar magnets placed near each other. Draw the magnetic field lines of the system.

Answer:
1. properties of magnetic field lines:

• The magnetic field lines of a magnet form continuous closed loops.
• The tangent to the field line at a given point represents the direction of magnetic field at that point.
• Flux density of magnetic field represents the strength of magnetic field.
• The magnetic field lines do not intersect

2.

Question 2.
The figure shows the magnetic field of earth.

1. Identify the labels A, B, C. (1)
2. The lines drawn on a map through places that have the same declination are called………(1)
3. The horizontal component of earth’s magnetic field at a place is 0.25 × 10^-4T and the resultant magnetic field is 0.5 × 10^-4 T. Find the dip and the vertical component of the earth’s magnetic field at the place. (2)

Answer:
1. the labels A, B, C:

• A – Magnetic equator
• B – Magnetic axis
• C – Declination

2. Isogonic lines

3. Horizontal component of earth’s magnetic field is
B_H = B cosδ
0.25 × 10^-4 = 0.5 × 10^-4 δ
δ = 60°
Vertical component of earth’s magnetic field is
Bv = B sin δ = 0.5 × 10^-4 sin 60 = 0.43 × 10^-4T.

Plus Two Physics Magnetism and Matter Five Mark Questions and Answers

Question 1.
When a magnetic needle is placed in a non-uniform magnetic field it experiences
1.

• a force but no torque
• a torque but no force
• force and torque
• neither a force nor a torque (1)

2. A bar magnet held perpendicular to a uniform magnetic field as in the figure. If the torque acting on it is to be reduced to 1/4^th by rotating the magnet towards the direction of the field, find the angle through which the magnet is to be rotated. (2)

3. State whether the potential energy of the magnet increases or decreases after rotation. Justify your answer. (2)
Answer:
1. force and torque

2. When the bar magnet is perpendicular to the field Torque is maximum
τ = MBsinθ = MBsin(90) = MB
When rotated through an angle θ, torque is

Angle through which the magnet is to be rotated is 90 – θ = 75.53°

3. Potential energy decreases. Potential energy is minimum when the magnet is parallel to the field. U = MBcosθ. When rotated to 0° (to make magnet parallel to the field) Potential energy decreases.

Students can Download Chapter 4 Moving Charges and Magnetism Questions and Answers, Plus Two Physics Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus Two Physics Chapter Wise Questions and Answers Chapter 4 Moving Charges and Magnetism

Plus Two Physics Moving Charges and Magnetism NCERT Text Book Questions and Answers

Question 1.
A Circular coil of wire consisting of 100 turns, each of radius 8.0cm carries a current of 0.40A. What is the magnitude of the magnetic field B at the centre of the coil?
Answer:
Given n = 100, r = 8.0cm = 8 × 10^-2
I = 0.4A, B = ?
At the centre of circular coil

= π × 10⁴T = 3.1 × 10^-4T.

Question 2.
A uniform field equal to 1.5T exists in a cylindrical region of radius 10.0cm, its direction parallel to the axis along east to west. A wire carrying current of 7.0A in the north to south direction passes through this region. What is the magnitude and direction of the force on the wire if

1. The wire intersects the axis?
2. The wire is turned from N-S to north-east-north-west direction.
3. The wire in the N-S direction is lowered from the axis by a distance of 4.0cm?

Answer:
1. F = \(\mathrm{Bl} \ell\) = 1.5 × 7 × \(\frac{20}{100}\) or F = 2.1 N acting vertically downwards.

2. Force will again be 2.1N.

3. F = \(\frac{1.5 \times 7 \times 16}{100}\) = 1.68N.

Question 3.
Two long and parallel straight wires A and B carrying currents of 8.0A and 5.0A in the same direction are separated by a distance of 4.0cm. Estimate the force on a 10cm section of wire A.
Answer:
Given I₁ = 8.0A, l₂ = 5.0A, r = 4.0cm = 0.04m
l = 10cm = 0.10m
Since

(direction is given by Fleming left-hand rule).

Plus Two Physics Moving Charges and Magnetism One Mark Questions and Answers

Question 1.
A straight wire of length 0.5 metre and carrying a current of 1.2 ampere is placed in uniform magnetic field of induction 2 tesla. The magnetic field is perpendicular to the length of the wire. Find the force on the wire is
Answer:
F = i/B = 1.2 × 0.5 × 2 = 1.2 N

Question 2.
To convert a galvanometer into a ammeter, one needs to connect a.
(a) low resistance in parallel
(b) high resistance in parallel
(c) low resistance in series
(d) high resistance in series
Answer:
(a) low resistance in parallel

Question 3.
A coil carrying electric current is placed in uniform magnetic field.
(a) torque is formed
(b) e.m.f is induced
(c) both a and b are correct
(d) none of these
Answer:
(a) torque is formed

Question 4.
Direction of motion of unit the positive test charge gives direction electric field. Direction of motion of…….gives direction of magnetic field.
Answer:
Unit north pole.

Question 5.
A magnetic system with zero dipole moment
(a) Solenoid
(b) current carrying coil
(c) current loop
(d) toroid
Answer:
(d) Toroid.

Question 6.
Find odd one regarding polarity solenoid, torroid, current carrying loop, bar magnet.
Answer:
Torroid (In this case North and South pole are absent).

Question 7.
The nature of path when a charged particle is projected 30° to the direction of magnetic field. (Helix, cycloid, straight line, parabola).
Answer:
Helix

Question 8.
What is solenoid?
Answer:
An insulated copper wire wound in the form of cylinder is called solenoid.

Question 9.
Write mathematical expression for ampere’s theorem.
Answer:
∫B.dl = µ₀I

Plus Two Physics Moving Charges and Magnetism Two Mark Questions and Answers

Question 1.
The figure shows a long straight conductor carrying a current I. A magnetic field is produced around the conductor.

What is the magnitude of the magnetic induction at a point ‘P’ which is at a distant ‘x’ from the conductor?
What is the shape of the magnetic line of force?

Answer:
1. B = \(\frac{\mu_{0} I}{2 \pi x}\). Magnetic field is directed in to the plane of paper.

2. Circular.

Question 2.
A particle of mass 6.65 × 10^-27 kg having positive charge equal to two times of electron, moves with a speed of 6 × 10⁵ m/s in a direction perpendicular to that of a given magnetic field of flux density 0.4 weber/m². Find the acceleration of the particle.
Answer:

q = 2e, v = 6 × 10⁵ m/s
B = 0.4, m = 6.65 × 10^-27 kg
∴ acceleration,

a = 1.15 × 10¹³ m/s².

Question 3.
Classify in to true or false.

1. The magnetic field in the middle of current carrying solenoid depends up on cross sectional area.
2. The magnetic field depends up on current.
3. The magnetic field depends up on the material of the core.
4. The magnetic field depends up on total numbers of turns per unit length.

Answer:

1. False
2. True
3. True
4. True

Question 4.
A short straight conductor carries current I

1. Write the expression for magnetic field due to this conductor.
2. Represent graphically the variation of magnetic field with distance from the wire.

Answer:
1. dB = \(\frac{\mu_{0}}{4 \pi} \frac{|d| \sin \theta}{r^{2}}\)

2.

Plus Two Physics Moving Charges and Magnetism Three Mark Questions and Answers

Question 1.
The magnetic field along the axis of a circular coil is found to be B = \(\frac{\mu_{\mathrm{o}} \mathrm{Ia}^{2}}{2\left(\mathrm{r}^{2}+\mathrm{a}^{2}\right)^{3 / 2}}\)
1. What is the magnetic field along the axis if r>>a
2.

• Compare the above magnetic field with the electric field along the axis of an electric dipole
• What is the equation of magnetic dipole moment?

Answer:
1. B = \(\frac{\mu_{0} / a^{2}}{2 r^{3}}\)

2.

• Electric field due to electric dipole, E = \(\frac{1}{4 \pi \varepsilon_{0}} \frac{P}{r^{3}}\) magnetic field due to magnetic dipole B = \(\frac{\mu_{0}}{4 \pi} \frac{m}{x^{3}}\).
• Magnetic moment m = IA

Question 2.
The circuit diagram for verifying Ohm’s Law is given below, A student unknowingly connects a galvanometer in the place of the ammeter.

1. What will happen to the galvanometer?
2. What modification has to be made in the galvanometer if he still wants to use the galvanometer in place of the ammeter?
3. Assuming voltmeter to be an ideal one, what will happen if the student interchanges the position of the voltmeter and ammeter?

Answer:

1. Galvanometer will be damaged.
2. use a shunt resistance.
3. No current flows, because an ideal voltmeter has infinite resistance.

Question 3.
Consider a galvanometer with a full scale deflection of 1 m A and resistance 100Ω.

1. How is the device connected in the circuit?
2. How can it be converted to an ammeter with full scale deflection 1 ampere?

Answer:
1. Connected in series.

2.

by connecting a shunt resistance. 0.1Ω in parallel with galvanometer, we can convert galvanometer in to ammeter.

Question 4.
Two infinitely long straight parallel wires carry currents I each as shown in fig.

1. Which law helps to find direction of magnetic field around a current carrying conductor?
2. What is the magnitude, direction of the magnetic fields at A, and C?

Answer:
1. Right hand grip rule.

2. The magnitude, direction of the magnetic fields at A, and C:

• A – outward to the plane of paper
• C-Inward to the plane of paper.

Question 5.
Analyze the figure and answer the following questions.

1. What is the nature of force between these conductors is……….
2. What is the field due to I₁ at second conductor?
3. What is the force experienced per unit length of II^nd conductor?

Answer:

1. Attractive
2. B= \(\frac{\mu_{0} d_{1}}{2 \pi r}\)
3. f = \(\frac{\mu_{0} l_{1} l_{2}}{2 \pi r}\)

Question 6.
“I am very light and present in every matter. When I move along the equator from east to west, I am pushed up. When I am stationary, no force”.

1. Name the force and write its expression.
2. Who am I?
3. What would happen if moved at the poles?

Answer:

1. Lorentz force in earth’s magnetic field F =qvB
2. Electron
3. The earth’s magnetic field at poles is perpendicular to the earth surface. When an electron move, it is pushed to one side, parallel to earth’s surface.

Plus Two Physics Moving Charges and Magnetism Four Mark Questions and Answers

Question 1.
The internal connections of a moving coil galvanometer is given in the fig (i) and fig (ii)

1. What is the use of moving coil galvanometer?
2. Which figure(i) or figure(ii) is used to measure Voltage?
3. Write an expression for resistance required to convert the moving coil galvanometer in to voltmeter.
4. If a very small resistance (eg, copper wire) is used to convert moving coil galvanometer in to voltmeter, will it work properly?

Answer:

1. Moving coil galvanometer is used to detect the presence of current
2. The instrument shown in figure (2) is used to measure voltage.
3. Resistance is connected in series with galvanometer. R = \(\frac{\mathrm{V}}{\mathrm{I}_{\mathrm{g}}}\) – G
4. No, A high resistance is required to convert galvanometer in to voltmeter.

Question 2.
When a charged particle enter normal to a uniform magnetic field, it take a circular path.

1. Name the particle accelerator using this principle.
2. Explain the working of that particle accelerator with relevant theory.
3. The neutrons can’t be accelerated using this partide accelerator. Why?

Answer:
1. Cyclotron.

2. Cyclotron:
a. Uses:
It is a device used to accelerate particles to high energy.

b. Principles:
Cyclotron is based on two facts

• An electric field can accelerate a charged particle.
• A perpendicular magnetic field gives the ion a circular path.

c. Working:

At certain instant, let D₁ be positive and D₂ be negative. Ion (+ve) will be accelerated towards D₂ and describes a semicircular path (inside it). When the particle reaches the gap, D₁ becomes negative and D₂ becomes positive.

So ion is accelerated towards D₁ and undergoes a circular motion with larger radius. This process repeats again and again. Thus ion comes near the edge of the dee with high K.E. This ion can be directed towards the target by a deflecting plate.

3. Charge of neutron is zero. Only charged particle can be accelerated using particle accelerated.

Question 3.
A current flows through a circular loop of radius r is shown in the figure.

1. What is the direction of magnetic field at ‘o’? (1)

2. Derive an equation for magnetic field at ‘o’ due to the circular loop carrying current i? (2)

3. If the loop splits into two equal halves as shown in figure. (1)

What will be the magnetic field at the center ‘o’?
Answer:
1. B = \(\frac{\mu_{0} I}{2 r}\) in t0 the plane of paper

2. Magnetic field on the axis of a circular current loop:
Consider a circular loop of radius ‘a’ and carrying current T. Let P be a point on the axis of the coil, at distance x from A and r from ‘O’. Consider a small length dl at A.
The magnetic field at ‘p’ due to this small element dl,
dB =\(\frac{\mu_{0} \mathrm{Idl} \sin 90}{4 \pi \mathrm{x}^{2}}\)

[since sin 90° -1]
The dB can be resolved into dB cosΦ (along Py) and dB sinΦ (along Px). Similarly consider a small element at B, which produces a magnetic field ‘dB’ at P. If we resolve this magnetic field we get.
dB sinΦ (along px) and dB cosΦ (along py¹)
dB cosΦ components cancel each other, because they are in opposite direction. So only dB sinΦ components are found at P, so total filed at P is

from ∆AOP we get x = (r² + a² )^1/2

Let there be N turns in the loop then,

Point at the centre of the loop:
When the point is at the centre of the loop, (r = 0) Then,

3. Zero

Question 4.
A boy connects a galvanometer directly to a cell of emf 1.5v to measure a current through a load 1Ω.

1. Which instrument can be used to measure the current in such a circuit?
2. What changes should be made in the galvanometer to measure such a high current? Explain using a circuit diagram.
3. The boy connected the galvanometer into a high current measuring device and he connected the device parallel to the load. What will be the observation. Justify.

Answer:
1. Ammeter

2.

A galvanometer can be converted into an ammeter by a low resistance (shunt) connected parallel to it.
Theory:
Let G be the resistance of the galvanometer, giving full deflection fora current I_g. To convert it into an ammeter, a suitable shunt resistance ‘S’ is connected in parallel. In this arrangement, Ig current flows through Galvanometer and remaining (I-I_g) current flows through shunt resistance.
Since G and S are parallel
P.d Across G = p.d across S
I_g × G =(I-I_g)S
S = \(\frac{\lg \mathrm{G}}{\left(1-\mathrm{l}_{\mathrm{g}}\right)}\)
Connecting this shunt resistance across galvanometer we can convert a galvanometer into ammeter.

3. Ammeter is a low resistance device. Hence it draws high current. This high current will damage it.

Question 5.
An electric charge will experience a force in uniform electric field. Similarly a moving charge experience a magnetic force (Lorentz) in magnetic field. The SI unit of magnetic field intensity is defined in terms of Lorentz Force.

1. Write the expression for magnetic Lorentz force.
2. Mention any two difference between electric field arid magnetic field.
3. Give an account of work done by Magnetic Lorentz force on moving charge and corresponding change in K.E.

Answer:
1.

2. Electric field is due to a charge, either in motion or at rest. Magnetic field is due to the motion of charge. Direction of electric force is colinear to electric field. Direction of magnetic force is perpendicularto magnetic field.

3. If velocity (displacement) is perpendicular to Lorentz force the work done will be zero and hence there will no change in K.E.

Question 6.
“Moving coil Galvanorrieter is a device used for detecting very feeble current”.

1. What is the working principle of a moving coil galvanometer?
2. Describe the construction and working of a moving coil galvanometer.
3. When a high current is passed through a moving coil galvanometer, it will get destroyed. How?

Answer:
1. Principle:
A conductor carrying current when placed in a magnetic field experiences a force, (given by Fleming’s left hand rule), τ = NIAB.

2.

A moving coil galvanometer consists of rectangular coil of wire having area ‘A’ and number of turns ‘n’ which is wound on metallic frame and is placed between two magnets. The magnets are concave in shape, which produces radial field.
Working :
Let T be the current flowing the coil, Then the torque acting on the coil. τ = NIAB, Where A is the area of coil and B is the magnetic field.

This torque produces a rotation on coil, thus fiber is twisted and angle (Φ). Due to this twisting a restoring torque (τ = KΦ) is produced in spring. Under equilibrium, we can write
Torque on the coil = restoring torque on the spring
NIAB = KΦ
Φ \(=\left(\frac{\mathrm{BAN}}{\mathrm{K}}\right)\) I
The quantity inside the bracket is constant for a galvanometer.
Φ ∝ I
The above equation shows that the deflection depends on current passing through galvanometer.

3. High current will produce large amount of heat. This heat will destroy coils in the galvanometer.

Question 7.
When a current carrying conductor is placed in a magnetic field it experiences a force.
1. Arrive at the expression forthe force experienced by the conductor. (2)
2. A conductor carrying current I direct out of the plane of the paper is lying in the magnetic field as in Fig. Draw the direction of force experienced by the conductor. (1)

3. If the conductor is lying parallel to the field what will be the force? (2)
Answer:
1. Consider a rod of uniform cross section ‘A’ and length ‘l’ Let ‘n’ be the number of electrons per unit volume (number density). ‘v_d’ be the drift velocityof electrons for steady current ‘I’.
Total number of electrons in the entire volume of rod =nAl
Charge of total electrons = nA l .e
‘e’ is the charge of a single electron.
The Lorentz force on electrons,

2.

3. Zero

Question 8.
A long straight conductor carrying current is placed near a current carrying circular loop as in the figure.

1. If B₁ is the field of the ring and B₂ the field due to straight conductor what will be the direction of B₁ and B₂ at O. (1)

2. The current through the loop and the conductor are 2A and the conductor is at as distance 20cm from the centre of loop. What should be the diameter of the loop so that the net field at O is zero. (3)
Answer:
1. B₁ into the plane and B₂ out of the plane.

2. B₁ is the field of the ring and B₂ the field of due to straight conductor.
B = B₁ – B₂ = 0
B₁ = B₂

2a = 40π × 10^-2m = 1,256m
Diameter d = 1.256 m.

Question 9.
A charged particle is travelling in the figure.

1. Name the force experienced by the charge in the region II. (1)
2. Give the expression for the net force experienced by the charge in the region II. (1)
3. If the charge reaches the region III without any change in its initial direction of motion find the velocity of the charged particle in terms of E and B. (2)

Answer:
1. Lorentz Force

2. F = q (E + v × B)

3. Electric and magnetic fields are perpendicular to each other and also perpendicular to the velocity of the particle. If the total force on the charge is zero and the charge will move in the fields undeflected. This happens when
qE = qvB or v = \(\frac{E}{B}\).

Question 10.
The medical diagnostic technique called magnetic resonance imaging (MRI) requires that patient lie in a strong magnetic field. It consists of two large solenoids, placed above and below.

1. What is solenoid?
2. Which law help you to find magnetic field due to solenoid? State the law.
3. Obtain an expression for magnetic field due to solenoid using the above law.
4. If the diameter of one of the MRI coil is increased without changing the current, does the magnetic field that it produce at its centre increases, decreases or stay the same? Justify.

Answer:
1. An insulated conducting wire wound in the form of cylinder is called solenoid.

2. Ampere’s circuital law:
Ampere’s circuital theorem states that the line integral of the magnetic field around any closed path in free space is equal to µ₀ times the net current passing through the surface.

3.

Consider a solenoid having radius Y. Let ‘n’ be the number of turns per unit length and I be the current flowing through it.

In order to find the magnetic field (inside the solenoid ) consider an Amperian loop PQRS. Let ‘l‘ be the length and ‘b’ the breadth

Applying Amperes law, we can write

Substituting the above values in eq (1), we get
Bl = µ₀ l_enc (2)
But l_enc = n l I
where ’nl ’ is the total number of turns that carries current I (inside the loop PQRS)
∴ eq (2) can be written as
Bl = µ₀nIl
B = µ₀ nI
If core of solenoid is filled with a medium of relative permittivity µ_r, then
B = µ₀µ_rnl

4. No change. Magnetic field is independent of radius.

Plus Two Physics Moving Charges and Magnetism Five Mark Questions and Answers

Question 1.
You are supplied with a galvanometer, resistor, and some connecting wires.

1. Using a circuit diagram, show how will you convert the given galvanometer into an ammeter.
2. Find the expression for the shunt resistance in the circuit.
3. A galvanometer is to be converted into an ammeter of range 0 – 1 A. Galvanometer has resistance 100Ω and the current for full scale deflection is 10mA. Find the length of the nichrome wire to be used as shunt.

Given, Resistivity ρ= 1.1 x 10^-6Ωm
Diameter of the wire = 1mm
Answer:
1.

2. Let I_g be the current through the galvanometer of resistance R_G and the shunt resistance be r_s.
Let I be the current to be measured by the converted ammeter.
We can write,
I_gR_G = (I – I_g)r_s
∴ r_s = \(\frac{I_{g} R_{G}}{\left(1-I_{g}\right)}\)

3. Given I = 1A
I_g = 10mA
R_G = 100Ω
Diameter = 1mm

Question 2.
Consider a conductor carrying current ‘I’, P is a point at a distance away from the conductor.

1. What is the direction of magnetic field at P? (1)
2. What are the factors affecting magnetic field at P due the element dl carrying current i? (1)
3. Derive an expression for magnetic field at P, if the current carrying conductor has infinite length? (2)
4. Draw a graph connecting Intensity of magnetic
   field and distance. (1)

Answer:
1. In to the plane of paper

2. dB = \(\frac{\mu_{0}}{4 \pi} \frac{|d| \sin \theta}{r^{2}}\)

• Current I
• Length of element dl
• sin of angle between element and line joining mid point of element and point.
• Inversely proportional to square of the distance between element and point.

3. Long straight conductor:
Consider a long straight conductor carrying ‘I’ ampere current. To find magnetic field at ‘P’, we construct a circle of radius r (passing through P).

According to Ampere’s circuital law we can write

4.

Question 3.
A student placed a rectangular loop carrying current in between the pole pieces of two magnetics and found that the loop is rotating.

1. What is the net force on the loop?
2. Write the expression for the torque experienced by the loop in vector form.
3. At what position will the coil be in stable equilibrium?
4. A wire of length 4m is bent in the form of a circular coil of single turn. A current 1A is flowing through the wire. If the coil is placed in a magnetic field of 0.4T find the maximum torque experienced by the coil.

Answer:
1. Zero

2.

3. θ = 0, τ = 0, Potential energy is minimum (Area vector of the coil is parallel to the direction of magnetic field.)

4. I = 4m
2πr = 4
r = \(\frac{4}{2 \pi}\)
Area = A = πr²
Maximum torque = NIAB = 1 × 1 × π × \(\left(\frac{4}{2 \pi}\right)^{2}\) × 0.4
= 0.509 Nm

Question 4.
Ampere’s theorem helps to find the magnetic field in a region around a current carrying conductor.

1. Draw the variation of intensity of magnetic field with the distance from the axis of a current carrying conductor.
2. A conductor carrying a current I is bent as shown in the figure. Apply Ampere’s theorem at the regions 1 and 2 shown in the figure.

Answer:
1.

2.

Question 5.
The force acting on a moving charge in a magnetic field is called magnetic Lorents force.

1. Write the equation of force experienced by a charged particle moving in a magnetic field.
2. Using the equation derive an expression for the force acting on a current carrying conductor of length T in a magnetic field B.
3. “A charge can move in a helical path in a magnetic field”. Do you agree with it? Explain.

Answer:
1.

2. Consider a rod of uniform cross section ‘A’ and length ‘ l ’. Let ’n’ be the number of electrons per unit volume (number density). ‘v_d’ be the drift velocity of electrons for steady current ‘I’.
Total number of electrons in the entire volume of rod = nA l
Charge of total electrons = nA l .e
‘e’ is the charge of a single electron.
The Lorentz force on electrons,

3. Yes, When an electron moves in a magnetic field with an angle θ, the electron undergoes for helical motion. The velocity of electron has two components, usinθ and ucosθ.

The component usinθ produces circular motion and ‘ucosθ’ produces translational motion. The combined effect of circular motion and translation motion will be helical motion.

Question 6.
A long wire is bent into a circular coil of one turn having radius ‘R’ and a current T is passed through it

1. Name the law to find the direction of magnetic field due to this current loop
2. Find an expression for magnetic field produced by this current loop at its centre
3. If the same wire is bent to a smaller radius Y having ‘n’ turns and send same current through it. Find the ratio of magnetic field at the centre in two cases.

Answer:
1. Right hand screw rule.

2. The magnetic field at a distance × from centre of loop is given by

3.

If wire is bend into smaller radius of n turns.

B₂ = n² B₁

Question 7.

A gas chamber is filled with hydrogen and a magnetic field is applied to it, then exposed to γ-ray. The γ-ray hits the hydrogen atom and produces high energy electron, low energy electron and positron (electron having + ve charge). The above photograph represents the trajectory of the particles. [Here magnetic field is applied Out of the plane of photo graph]

1. Which force drives the particle in a circular path and write the mathematical from.
2. Obtain a general expression for radius of the circular path.
3. Analyse the figure and match the columns given below.

Answer:
1. Magnetic Lorentz force

2. The centripetal force required for rotation is given magnetic Lorentz force Hence we can write

3. Analyse the figure and match the columns given below:

• Low energy electrons – B
• High energy electron – C
• Positron – A

Question 8.
A proton, an electron, a neutron, and an alpha particle are entering a region of uniform magnetic field with same velocities. The tracks of these particles are labelled.

1. Identify the tracks of each particle. (1)
2. Write the expression for the force experienced by a charged particle in the magnetic field in vector form. (1)
3. If the proton is moving at 90° to the uniform magnetic field what will be the change in kinetic energy of the proton? Give reason. (1)
4. An electron with energy 1 keV is entering a uniform magnetic field of 0.04T at an angle 60° with the field. Predict the path of the electron and find the characteristics of the path. (2)

Answer:
1. Identify the tracks of each particle:

• Path 1 – proton
• Path 2 – alpha particle
• Path 3 – neutron
• Path 4 – electron

2.

3. Zero. Since the force is perpendicular to the direction of velocity work done is zero.

4. KE = 1 keV = 1 × 10³ × 1.6 × 10^-19 = 1.6 × 10^-16


= 8.39 × 10^-3.

Question 9.
A current carrying conductor is bent in the form of a circular ring and is placed in the plane of the paper.

1. What is the direction of the magnetic field at the centre of the ring? (1)
2. Arrive at the expression for the magnetic field at a point on the axis of the ring. (3)
3. Another identical ring carrying the same current is brought with its axis perpendicular to the axis of the first as in figure. Find the magneticfield at the common centre. Calculate the angle between the net magnetic field and the axis of any one of the coils. (1)

Answer:
1. Out of the plane of the ring.

2.

Consider a circular loop of radius ‘a’ and carrying current ‘I’. Let P be a point on the axis of the coil, at distance x from A and r from ‘O’. Consider a small length dl at A. The magnetic field at ‘p’ due to this small element dl,

[since sin 90° -1]
The dB can be resolved into dB cosΦ (along Py) and dB sinΦ (along Px). Similarly consider a small element at B, which produces a magnetic field ‘dB’ at P.

If we resolve this magnetic field we get. dB sinΦ (along px) and dB cosΦ (along py¹) dB cosΦ components cancel each other, because they are in opposite direction. So only dB sinΦ components are found at P, so total filed at P is
B = ∫dBsinΦ

but from ∆AOP we get, sinΦ = a/x
∴ We get,

Let there be N turns in the loop then,

At the center of the loop,
r= 0

3. Magnetic fields are as shown in the fig.

The diagonal gives the resultant field.

Question 10.
An electron revolving round the nucleus acts as a magnetic dipole.

1. Which force provides the centripetal force for electron? (1)
2. Write the expression for the magnetic dipole moment of electron in vector form. What is the angle between direction of the magnetic moment and direction of angular momentum? (2)
3. A charge 2mC is moving through a circular path of radius 0.15m with frequency 1000Hz. Find the magnetic moment associated with the charge path. (2)

Answer:
1. Electrostatic force between electron and the nucleus.

2. Vectorially

The magnetic moment of the electron is opposite in direction to the angular momentum.
∴ Angle = 180°.

3. Revolving charge behaves as a current loop. Hence Magnetic field is given as

I = \(\frac{q}{T}\) = qv = 2 × 10^-3 × 100 = 0.2A
Magnetic moment = IA = 0.2 × π × 0.15²
= 0.0141 Am.

Question 11.
You are supplied with a galvanometer, resistor, and some connecting wires.

1. Using a circuit diagram, show how will you convert the given galvanometer into an ammeter. (1)
2. Find the expression for the shunt resistance in the circuit. (2)
3. A galvanometer is to be converted into an ammeter of range 0 -1 A. Galvanometer has resistance 100Ω and the current for full-scale deflection is 10mA. Find the length of the nichrome wire to be used as shunt. (3)

Given, Resistivity ρ = 1.1 × 10^-6Ωm
Diameter of the wire = 1 mm
Answer:
1.

2. Let I_g be the current through the galvanometer of resistance R_G and the shunt resistance be r_s. Let I be the current to be measured by the converted ammeter.
We can write,

3. Given I = IA
I_g = 10mA
R_G = 100Ω
Diameter = 1mm

Students can Download Chapter 2 Theory of Consumer Behaviour Questions and Answers, Plus Two Economics Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus Two Economics Chapter Wise Questions and Answers Chapter 2 Theory of Consumer Behaviour

Plus Two Economics Theory of Consumer Behaviour One Mark Questions and Answers

Question 1.
Suppose a consumer’s preferences are monotonic. Which bundle of goods the consumer will select over the bundle (15,15), (10,12) and (12,12).
Answer:
Consumer prefers the bundle (15,15) over the other bundles.

Question 2.
In drawing an individual demand curve, all but one of the following are kept constant.
(a) Price of the commodity
(b) Price of other commodities
(c) Income of the consumer
(d) Taste and preference of the consumer
Answer:
(b) Price of other commodities

Question 3.
Find out economic terms.

1. Bundles that are on or below the budget line.
2. Consumer prefers the bundle which has more of the goods compared to the other bundle.
3. A group of indifference curves.

Answer:

1. Budget set
2. Monotonic preferences
3. Indifference map

Question 4.
Slope of indifference curve shows.
(a) Price ratio (rule)
(b) DMRS
(c) DMU
(d) None of these
Answer:
(b) DMRS

Question 5.
In the case of inferior goods, the relationship between income and quantity demanded in.
(a) negative
(b) positive
(c) constant
(d) cannot be predicted
Answer:
(a) negative

Question 6.
Elasticity in a rectangulas hyperbola is:
(a) 0
(b) a
(c) 1
(d) 0.5
Answer:
(c) 1

Question 7.
Rise in demand due to fall in price is called:
(a) Increase in demand
(b) Expansion of demand
(c) Contraction of demand
(d) Decrease in demand
Answer:
(b) Expansion of demand

Question 8.
If demand falls from 100 to 75 units due to rise in price from 10 to 15, the value of elasticity is…
(a) 1
(b) 0.5
(c) 0
(d) 2
Answer:
(b) 0.5

Plus Two Economics Theory of Consumer Behaviour Two Mark Questions and Answers

Question 1.
Suppose Raju is indifferent to bundles (8,7) and (7,7). Are the preferences of Raju are monotonic?
Answer:
No, if his preferences are monotonic, he will prefer the bundle (8,7) over (7,7).

Question 2.
Consider a market where there are 3 consumers and suppose their demands for the good are given as follows:

Calculate the market demand for the good.
Answer:

Question 3.
Complete the following table.

Answer:

Question 4.
Pick out the odd one and justify your answer. Bread and butter, Pen and Ink, Butter and Jam, Tennis ball and Tennis racket.
Answer:
Butter and Jam. Others are complementary goods.

Question 5.
State the law of demand. Test the applicability of the law in the status symbol goods.
Answer:
Law of demand – “other things remaining the same as the price of a commodity falls, its quantity demanded increases and vice versa”.

Certain ostentatious goods like luxury cars; diamonds, etc. are exceptions to the law of demand. These goods are considered as status symbol goods consumed by the rich. The status goes up as price increases. Therefore, the demand for these goods increases as their price increases.

Question 6.
The demand function of a commodity is Q = 30 – 2 P. If it is a free good, quantity demanded would be.
Answer:
If the commodity is a free good, the price = 0
Q = 30 – 2 × 0
= 30 – 0 = 30

Question 7.
When the elasticity of demand for a product is unitary,

1. Name the shape of the demand curve?
2. Give the value of price elasticity of demand?

Answer:

1. Rectangular hyperbola
2. Value of price elasticity of demand is unity

Question 8.
Consider the demand curve D(p) = 10 – 3p. What is the elasticity at price 2?
Answer:
D(P) = 10 – 3p
Since P = 2, we get
D(P) = 10 – 3 × 2
= 10 – 6 = 4
Σd = \(\frac{\Delta Q}{\Delta P}=\frac{4}{2}\) = 2
Thus there is elastic demand.

Plus Two Economics Theory of Consumer Behaviour Three Mark Questions and Answers

Question 1.
Suppose a consumer buys bundles of good 1 and good 2. His income is given as ‘M’ and it is fully spent. If the prices of good 1 and good 2 are P₁ and P₂ respectively, state the consumer’s budget constraint.
Answer:
We assume that the consumer buys bundles of good 1 and good 2. The consumer’s consumption expenditure is limited by his income. Given the prices of good 1 and good 2 as P₁ and P₂ respectively and his income as ‘M’, consumer’s budget constraint can be represented as P₁X₁ + P₂X₂ ≤ M

Question 2.
Match the following

Answer:

Question 3.
Given below an indifference curve.

1. State the meaning of an indifference curve.
2. Identify the points A, B, C and D on the 1C.

Answer:
1. An indifference curve shows different bundles that give the consumer the same level of satisfaction. In other words, an indifference curve joins all points representing bundles which are considered indifferent by the consumer.

2. Points A and B are on the indifference curve indicating the same level of satisfaction. Point C lies above the indifference curve representing the preferred bundles. Point D lies below the indifference curve showing the inferior bundles.

Question 4.
Two demand function equations are given below.
QD₁ = 60 – 10P
QD₂ = 80 -10P
a. Derive two demand schedules forthe above de-mand functions (Take the values of P as 1,2,3,4,5)
QD₁= 60- 10P
QD₂ = 80 – 10P
P = 1,2,3,4,5
Answer:

Question 5.
Fora linear demand curve,
d (p) = a – bp; 0 < p < a/b = 0; p> a/b

1. State the meaning of ‘a’ and -b?
2. What does the slope of the demand curve mean?

Answer:

1. In the equation of linear demand curve, ‘a’ is the vertical intercept and-b is the slope of the demand curve.
2. The slope of the demand curve measures the rate at which demand changes with respect to its price.

Question 6.
Observe the three budget lines drawn below.

If AB is The Intial Budget Line, What Causes The Shift in budget line.

1. from ABtoAB
2. from ABtoA

Answer:

1. Fall in price of good 1
2. A rise in income or fall in prices of both good 1 & good 2.

Question 7.
Choose the correct answer from the given multiple choices.
1. Which of the following goods has more elastic demand?

• Rice
• Computer
• Electricity
• Life-saving drugs
• Salt

2. Identify the nature of demand curve when elasticity of demand is equal to one.

• Perfectly elastic demand
• Rectangular hyperbola
• Parallel to Vertical axis.
• Perfectly inelastic demand
• Parallel to horizontal axis

Answer:

1. computer
2. rectangular hyperbola

Question 8.
Compare the slope of the budget line and slope of the indifference curve.
Answer:
The slope of the indifference curve shows the rate at which the consumer is willing to substitute with others. Here the substitution is in terms of satisfaction. The slope of the budget line shows the rate at which a consumer is able to substitute our good for others. Here the substitution is in terms of price.

Question 9.
Indicate for each of the following situations whether it would shift the demand curve upward or downward

1. The price of substitute falls.
2. Consumer’s income increases
3. There is sudden rise in population.
4. Complementary goods become more expensive.
5. There is possibility of further fall in price, nilei
6. New cheaper substitutes of the commodity appear in the market.

Answer:

1. downward
2. upward
3. upward
4. downward
5. downward
6. downward

Question 10.
Classify the following goods into two based on their elasticity.
Petrol, medicine, tomatoes, car, garments, salt
Answer:

Question 11.
Imagine that you are the finance minister of Kerala. You want to raise more tax revenue. How will you use elasticity in your tax proposals?
Answer:
As finance minister, I will raise taxes on goods like cigarettes, liquor, and luxury products. These goods have inelastic demand and therefore, their demand will not decline in proportion to the price rise. This will help to raise more tax revenue.

Question 12.
Categorize the following into substitutes and complementaries.
Coffee and tea, pen and ink, bread and jam, scooter and petrol, shoes and chappels, airplane and train.
Answer:
1. Substitutes:

• Coffee and tea
• Shoes and chapels
• Airplane and train

2. Complementaries:

• pen and ink
• bread and jam
• scooter and petrol

Question 13.
The price of X falls from ₹8 per unit to t 6. Consequently, the quantity demanded increased from 80 to 100. Calculate the price elasticity of demand.
Answer:
\(\frac{\Delta Q}{\Delta P} \times \frac{P}{2}\)
ΔQ = 20
ΔP = 2
P = 8
Q = 80
ep = \(\frac{20}{2} \times \frac{8}{80}=\frac{160}{160}=1\)
ep = 1
This is unitary elastic demand

Question 14.
State whether true or falls

1. The demand curve is generally sloping upward
2. Demand for cosmetic is elastic
3. Utility is want satisfying power of a commodity

Answer:

1. False. Demand curve slops downward.
2. True
3. True

Question 15.
What do you mean by inferior goods? Give some example?
Answer:
Inferior goods are those goods whose demand decreases with rise in the income and demand increases with the fall in the income.

Question 16.
Give an account of price elasticity of demand.
Answer:
Price elasticity of demand is a measure used in economics to show the responsiveness, or elasticity, of the quantity, demanded of a good or service to a change in its price. It was devised by Alfred Marshall. The formula for the

The above formula usually yields a negative value, due to the inverse nature of the relationship between price and quantity demanded, as described by the “law of demand”.

This measure of elasticity is sometimes referred to as the own-price elasticity of demand for a good, i.e., the elasticity of demand with respect to the good’s own price, in order to distinguish it from the elasticity of demand for that good with respect to the change in the price of some other good, i.e., a complementary or substitute good. The latter type of elasticity measure is called a cross-price elasticity of demand.

Question 17.
Given the level of income and market prices, the rational consumer wants to attain the maximum level of satisfaction. Using the budget line and indifference curve that you have studied, answer the following questions.

1. Construct a diagram showing the consumer’s equilibrium.
2. What condition is satisfied at this equilibrium point?

Answer:
1.

2. Price ratio = Marginal Rate of Substitution

Question 18.
Two diagrams related to demand are given below. What do they represent?

Answer:

• Figure 1 – Movement along the demand curve due to change in price.
• Figure 2 – Shift in demand due to change in non price factor.

Question 19.
If other things remaining same, graphically explain what happens to the demand curve for chicken if there is

1. An increase in the price of fish.
2. A decrease in family income.
3. An increase in the price of chicken.

Answer:
1.

2.

Plus Two Economics Theory of Consumer Behaviour Four Mark Questions and Answers

Question 1.
“Price elasticity of demand is different at different points on the linear demand curve” Prove this point diagrammatically.
Answer:
On the linear demand curve, Price elasticity of demand varies from point to point. It can be seen from the linear demand given below. As we move from the higher point to lower point the value of elasticity goes on decreasing.

Question 2.
Locate the optimum bundle of the consumer in a diagram. Also, suggest the conditions for the consumer’s optimum.
Answer:
The optimum bundle of the consumer is located at the point where the budget line is tangent to one of the indifference curves. It is drawn below.

1. Condition I: Budget line should be tangent to the indifference Curve
2. Condition II: Slope of 1C (MRSxy) should be equal to slope of budget line (Price Ratio)

Question 3.
Draw a demand curve at all points of which price elasticity remains the same. Also, name the demand curve and give the equation for it.
Answer:

The demand curve at which all points represent same elasticity is called a rectangular hyperbola. The equation is xy = c, where, x and y are two variables and c is a constant. With such a demand curve, no matter at what point, the consumer consumes at a constant rate.

Question 4.
Gopan buys 8 kg of rice at price ₹15 per kg. It is found that the price elasticity of demand is 2. At what price he will buy 13 kg of rice?
Answer:
Price elasticity of demand means the degree of responsiveness of demand due to change in price. The formula for price elasticity of a product is,
Ep = \(\frac{\Delta Q}{\Delta P} \times \frac{P}{Q}\)
Here the price elasticity of demand = 2
\(\frac{\Delta Q}{\Delta P} \times \frac{P}{Q}\) = 2
\(\Delta P=\frac{8.12}{2}\)
ΔP = 4.06
new price is 13 – 4.06 = 8.96

Question 5.
Show how the following changes affect the budget line
Answer:

1.  Increase in income of the consumer
2. Decrease in income
3. Fall in the price of good 1
4. Rise in the price of good 1

Answer:

Question 6.
Suppose there are 2 consumers in the market for a good and their demand function are as follows Find out market demand function.
Answer:
First individuals demand function Second individual’s demand function = d₂ (P) = 30 – 2p
∴ Market demand function = d₁ (P) = d₂ (P)
= 20 – p + 30 – 2p
= 50-3p

Question 7.
Derive the slope of budget line, using symbols?
Answer:
The slope of the budget line measures the amount of change in good 2 required per unit of change in good 1 along the budget line. Consider any two points (X₁, x₂) and (x₁ + ΔX₁,x₂ + Δx₂) on the budget line.

Question 8.
When price of orange is ₹4, consumer buys 50 units of it. The price elasticity is -2. How many units will the consumer buy at ₹3 per unit of orange?
Answer:
Σ d = -2
When P = 4, q = 50
When P = 3, q = ?

100 = 4 Δ q
Δ q = 100/4 =25
∴ New quantity = q + Δ q
= 50 + 25 = 75

Plus Two Economics Theory of Consumer Behaviour Five Mark Questions and Answers

Question 1.
The consumer has an income of Rs. 100. He wants to consume two goods X and Y. Prices of X and Y are Rs. 20 and 10 respectively.

1. State the equation of the budget line.
2. How much of good X he can buy if he spends entire income on good X.
3. How much of good Y he can buy if he spends entire income on good Y.

Answer:
1. The equation of the budget line is given as P₁ + P₂X₂=M
Where P₁ and P₂ are prices of good 1 and good 2 respectively. X₁ and X₂ are quantities of two goods. ‘M’ denotes the income of the consumer.

2. 5 units of good X.

3. 10 units of good Y

Question 2.
A consumer wants to consume two goods. The prices of the two goods are ₹4 and ₹5 respectively. The consumer’s income is ₹20.

1. Write down the equation of the budget line
2. How much of good 1 can the consumer consume if he spends his entire income on the good?
3. How much of good 2 can the consumer consume if he spends his entire income on the good?
4. What is the slope of the budget line?

Answer:
1. the equation of the budget line is p₁x₁+ p₂x₂= M
where P₁ and P₂ are prices of good1 and good 2. x-s and x2 are quantities of goods and M is his money income,

2. X₁ = M/ P₁
= 20/4 = 5 units
X₂ = M/ P₂
= 20/5 = 4 units

3. slope of the budget line is
= -P₁/P₂
= -4/5
= – 0.8 units

Question 3.
One important factor influencing demand is price of the product.

1. Can you make a list of four other factors that influence the demand for a good?
2. Also, establish the relationship between the factor identified and the demand for the product.

Answer:

• Column 1. Income, price of substitutes, advertisement, tastes & preferences
• Column 2. Positive, Negative, Positive, Positive

Question 4.
A few goods are given below. State whether the demand for the product is elastic or inelastic. Justify your answer.
Rice, salt, car, life-saving drugs, computer, electricity
Answer:

1. Rice – Inelastic – Essential good Car – Elastic – Luxury good.
2. Salt – Inelastic- Insignificant share in total expenditure. Life saving drugs – Inelastic – Not possible to postpone purchase.
3. Computer- Elastic demand,Non-essential good. Electricity – Inelastic – No substitutes

Question 5.
As you know elasticity of demand is influenced by several factors. Observing the nature of good given in the first column, complete the following table. Write whether the demand for the product is elastic or in¬elastic and also the reason.

Answer:
Column 2 – Column 3
Elastic – luxury product
Elastic – close substitutes are available
Elastic – no substitute
Elastic – Essential good
Elastic – Essential good

Question 6.
The diagram below shows the demand curves of commodities and b which are complementary to each other.

1. What are complementary goods?
2. Write two examples each for commodity
3. The diagram shows the changes in the demand curve of commodity ‘b’ due to a fall in the price of commodity ‘a’.

Answer:

1. Complementary goods are those goods demanded jointly for the consumption of one good, it requires other good too.
2. Car, petrol, mobile phone, sim card, etc.
3. When the price of ‘a1 comes down more of ‘a’ will be demanded. This would result in an increase in the demand for its complementary ‘b’.

Plus Two Economics Theory of Consumer Behaviour Eight Mark Questions and Answers

Question 1.
Prepare a seminar paper on the measurement of price elasticity of demand.
Answer:
Methods of measuring elasticity
Elasticity can be measured by using methods such as percentage method, linear method/point method, and expenditure method.
The detailed descriptions of the methods are as follows:
1. Percentage method:
Percentage method is also known as the proportionate method. As per percentage method estimate the elasticity of demand by dividing the percentage change in quantity demanded by the percentage change in price as given earlier. Thus, the formula for estimating elasticity of demand through percentage method is given as The procedure of computing elasticity using percentage method is provided in the example: 1.

2. Linear method/point method:
It is popularly known as the mathematical method of measuring price elasticity of demand. It is also known as point method of measuring elasticity of demand. The elasticity would be different on different points in a straight-line demand curve.

The following points can be observed from the above figure:
a. When a straight-line demand curve cut the X-axis, the elasticity of demand would be zero (e_D = 0) (perfect inelastic demand).

b. The elasticity of demand at the midpoint on a straight-line demand curve would be one (e_D = 1) (unitary elastic demand).

c. When a straight-line demand curve cut the Y-axis, the elasticity of demand would be zero (e_D = a) (perfect elastic demand).

d. Between the midpoint and the point where the demand curve cuts the X-axis on a straight line would be less than one (inelastic demand) (e_D = <1).

e. Between the midpoint and the point where the demand curve cuts the Y-axis on a straight line would be more than one (elastic demand) (e_D>1).

3. Expenditure method:
The total expenditure on a commodity can be find out by multiplying the quantity of commodity with its price. As per expenditure method, the price elasticity is measured by comparing the change in price and the change in total expenditure. Three possibilities may occur in this context.

a. If the total expenditure does not change even if there is a price change, then elasticity would be 1 or unity (e_D = 1)

b. If the total expenditure decreases as a result of increase in price or total expenditure increases as a result of fall in price, it would be more elastic (e_D> 1).

c. If the total expenditure increases as a result of decrease in price or total expenditure decreases as a result of rise in price, it would be less elastic (e_D = <1).

Question 2.
The demand curve for apple is given below. Show the effect on the demand curve for apple due to the following factors.

1. A newspaper report stating the health benefit of apple
2. The price of apple increases.
3. What is price elasticity of demand? What do you think about the price elasticity of apple. Justify your answer.

Answer:
1. The demand curve for apple shifts rightward. Taste and preference arise in favour of apple.

2. There is a movement along the demand curve. This is due to an increase in price. Quantity demand of apple falls.

3. It is the responsiveness of quantity demanded to a change in price.
\(\mathrm{Ped}=\frac{\% \mathrm{Δad}}{\% \mathrm{ΔP}}\)

Students can Download Chapter 13 Amines Questions and Answers, Plus Two Chemistry Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus Two Chemistry Chapter Wise Questions and Answers Chapter 13 Amines

Plus Two Chemistry Amines One Mark Questions and Answers

Question 1.
The reaction of aniline with benzoyl chloride gives
(a) benzoin
(b) benzanilide
(c) benzalaniline
(d) benzamide
Answer:
(b) benzanilide

Question 2.
Nitromethane on reaction with H₂/Pd gives ____________
Answer:
Ethanamine (CH₃CH₂NH₂)

Question 3.
Say TRUE or FALSE
Only aliphatic primary amines give a foul smelling compound with CHCl₃ and alcoholic potash.
Answer:
False

Question 4.
When benzene diazonium salt solution is treated with KI ___________ is formed.
Answer:
lodo benzene (C₆H₅I)

Question 5.
Identify ‘Z’ in the sequence:

(a) Nitrobenzene
(b) Benzene
(c) Fluorobenzene
(d) Phenol
Answer:
(a) Nitrobenzene

Question 6.
Amine that cannot be prepared by Gabriel Phthalimide Synthesis is _________
Answer:
Aniline

Question 7.
Phenyl isocyanide, is prepared from aniline by ________
Answer:
Carbylamine reaction

Question 8.
Secondary amines can be prepared by ___________
Answer:
Reduction of nitro compounds

Question 9.
By which process aniline can be purified ___________
Answer:
Steam distillation

Question 10.
A primary amine that can be obtained both by the reduction of cyanides and amides is ___________
(a) methyl amine
(b) benzylamine
(c) aniline
(d) isopropylamine
Answer:
(b) benzylamine

Question 11.
The amine which will not liberate nitrogen on reaction with nitrous acid is __________
Answer:
t-butyl amine

Plus Two Chemistry Amines Two Mark Questions and Answers

Question 1.
Ammonia is less basic than aniline.

1. What is the reason for low basic character of aniline compared to ammonia?
2. Draw the resonating structures of aniline.

Answer:
1. In aromatic amines the lone pair on nitrogen is in conjugation with benzene ring due to resonance effect and thus making it less available for protonation. Hence basic character is less than that of ammonia.
2.

Question 2.
Two compounds are functional isomers of each other. On reduction one gives primary amine and the other gives secondary amine.

1. Identify the class of compounds.
2. Explain the reduction reaction.

Answer:

1. Cyanides and Isocyanides.
2. When cyanides are reduced using LiAlH₄ primary amines are obtained. Whereas when isocyanides are reduced using LiAlH₄ secondary amines are obtained.

Question 3.
When alkyl halide is treated with alkali metal cyanide, cyanides are obtained as the major product. Assume that AgCN is used instead of NaCN.

1. What will be the product?
2. Justify.

Answer:

1. Isocyanide
2. Silver cyanide is predominantly covalent. Hence nitrogen atom is free to donate electron pair forming isocyanide as the main product.

Question 4.
How is sulphanilic acid prepared from aniline?
Answer:
Aniline reacts with concentrated sulphuric acid to form anilinium hydrogensulphate which on heating with sulphuric acid at 453-473 K produces sulphanilic acid.

Question 5.
Write chemical equations for the preparation of benzene, fluorobenzene, and nitrobenzene from benzenediazonium chloride.
Answer:

Question 6.

1. What are Schiff s bases?
2. How are they formed?

Answer:
1. Schiff’s bases are substituted imines.
2. These are formed when 1° amines are treated with carbonyl compounds.

Question 7.
What are the products formed by the reaction of ethanolic NH₃ with C₂H₅CI? Write the chemical equation.
Answer:
A mixture of ethanamine, N-ethylethanamine and N,N-diethylethanamine are formed

Question 8.
Gabriel phthalimide synthesis is preferred for synthesising primary amines.
Answer:
Gabriel phthalimide synthesis involves the conversion of alkyl halide (R – X) to 1° amine (R – NH₂). Ammonolysis of R – X, on the other hand give 2°, 3° and quaternary salt as other byproducts. Hence, for the production of pure 1° amines, Gabriel phthalimide synthesis is preferred to ammonolysis reaction.

Plus Two Chemistry Amines Three Mark Questions and Answers

Question 1.
Nitrogen containing functional groups are classified into different types.

1. Which are they?
2. Explain one method to prepare cyanide.
3. Give chemical equations.

Answer:

1. Nitro compounds, Amines, Cyanides, Isocyanides and Diazo compounds.
2. When alkyl halides on heating with alcoholic KCN or NaCN cyanide is obtained.
3. R – X + KCN → R-CN + KX. e.g. CH₃ – CH₂ -Br + KCN → CH₃CH₂CN + KBr

Question 2.
Consider the following chemical equations:

1. a) Identify ‘A’ and ‘B’.
2. b) Name the reactions.
3. c) Give any one method to prepare beznene diazonium chloride.

Answer:
1. A – LiAIH₄ B – Br₂/KOH
2.

• i) is reduction of acid amide.
• ii) is Hoffmann’s bromamide degradation reaction.

3. Benzene diazonium chloride can be prepared by diazotization of aniline. It can be done by treating aniline with sodium nitrite and HCI at 273-278 K.

Question 3.
Chlorobenzene can be prepared from benzene diazonium chloride in two ways.

1. a) Do you agree with it?
2. b) Which are the two ways?
3. c) Write the chemical equation for the reactions.

Answer:
1. Yes.
2. By Sandmeyer’s reaction and Gattermann’s reaction.
3. Sandmeyer’s reaction

Gattermann’s reaction

Question 4.
Match the following:

Answer:

Question 5.
Diazonium salts are very important class of compounds used for synthesis of variety of aromatic compounds.

1. How is nitrobenzene prepared from diazonium salt?
2. Give an example for coupling reaction.
3. Give an important use of diazonium salt.

Answer:

1. Benzene diazonium chloride is treated with fluoroboric acid to get benzenediazonium fluoroborate which when heated with aqueous sodium nitrite solution in the presence of copper, nitrobenzene is formed.

2. When benzenediazonium chloride is coupled with aniline in acid medium, p-aminoazobenzene (an yellow azo dye) is formed.

3. It can be used as intermediate for the synthesis for many organic compounds.

Question 6.
An aromatic compound ‘A’ on treatment with aqueous ammonia and heating forms compound ‘B’ which on heating with Br₂ and KOH forms a compound ‘C’of molecular formula C₆H₇N. Write the structures and IUPAC names of compounds A, B, and C.
Answer:
Hoffman bromide reaction

Question 7.
Write the IUPAC names of the following compounds and classify them into primary, secondary and tertiary amines.

1. C₆H₅NHCH₃
2. (CH₃CH₂)₂NCH₃
3. m-BrC₆H₄NH₂

Answer:

1. N-Methylbenzenamine (2° amine)
2. N-Ethyl-N-methylethanamine (3° amine)
3. 3-Bromobenzenamine (1° amine)

Plus Two Chemistry Amines Four Mark Questions and Answers

Question 1.
C₆H₅NH₂ gives a foul smelling compound ‘A’ with chloroform in presence of KOH (alcoholic).

1. What is compound ‘A’?
2. Write the chemical equation for the reaction.

Answer:

a) ‘A’ is phenyl isocyanide (or phenyl carbylamine)
b) Carbyl amine reaction

Question 2.
1. In a group discussion, a student argued that alkyl amines are more basic than NH₃.

• Is it correct?
• Justify your answer with suitable explanation.

2. Arrange the following amines in the decreasing order of basic strength in aqueous solution.
CH₃NH₂, (CH₃)₂NH, NH₃, (CH₃)₃N Justify.
Answer:
1.

• Yes.
• Electron realeasing inductive effect (+l) of alkyl groups increases the availability of lone pair on nitrogen.

2. (CH₃)₂NH > CH₃NH₂ > (CH₃)₃N > NH₃
Inductive effect is maximum for 3° amines. At the same time steric hindrance is maximum for 3° amines. An interplay of the inductive effect, solvation effect and steric hindrance of the alkyl group decides the basic strength of alkylamines.

Question 3.

a) Watch the above diagram and fill the labelled boxes A, B, C, and D.
b) If you are treating B with nitrous acid, predict the product that can be formed.
Answer:
a)

b) CH₃ CH₂ – OH

Question 4.
a) Benzenediazonium chloride is a very important compound in organic chemistry. Give the structure. How it is prepared?
b) How phenol and iodobenzene are prepared from the above compound?
Answer:

Question 5.

Answer:

Question 6.
a) Arrange the following in the increasing order of basic strength.
C₆H₅NH₂, C₆H₅N(CH₃)₂, (C₂H₅)₂NH, CH₃NH₂
b) How will you convert aniline to phenol?
Answer:
a) C₆H₅NH₂ < C₆H₅N(CH₃)₂ < CH₃NH₂ < (C₂H₅)₂NH

Question 7.

1. How is nitrous acid prepared in the laboratory?
2. A student treated methylamine and aniline separately with nitrous acid. What are the products formed in each case? Give chemical equations.

Answer:
1. By treating hydrochloric acid with sodium nitrite,
2. Methyl amine reacts with nitrous acid to form methyldiazonium salt which being unstable, liberates nitrogen gas quantitatively and forms methanol.

Aniline reacts with nitrous acid at low temperature (273-278 K) to form benzenediazonium salt, a very important compound used in synthetic organic chemistry.

Question 8.
Give one chemical test to distinguish between the following pairs of compounds.

1. Methylamine and dimethylamine
2. Secondary and tertiary amines
3. Ethylamine and aniline
4. Aniline and benzylamine
5. Aniline and N-methylaniline

Answer:
1. Methyl mine is a 1° amine and so it gives the carbylamine test. When methylamine is warmed with chloroform and alcoholic solution of KOH, foul smelling methyl isocyanide is formed.

Dimethylamine is a 2° amine and hence it does not answer carbylamine test. Or they can be distinguished by Hinsberg’stest.

2. Secondary and tertiary amines can be distinguished by Hinsberg’s test.
Secondary amines react with Hinsberg’s reagent (benzene sulphonyl chloride) to form N, N- dialkyl benzene sulphonamide which is insoluble in alkali.
Tertiary amines do not react with Hinsberg’s reagent.

3. Ethylamine is an aliphatic 1° amine. When treated with HNO₂ (NaNO₂ and HCI) it forms ethanol with liberation of N₂ gas.

CH₃ – CH₂ – NH₂ + HNO₂ → CH₃ – CH₂ – OH + N₂ + H₂O

Aniline is an aromatic 1° amine. When treated with HNO₂ at low temperature (273 – 278 K) it gives benzene diazonium chloride which undergoes coupling reaction with phenol to form an orange azo dye.

C₆H₅NH₂ + HNO₃ + HCI → C₆H₅N₂⁺ + Cl^– + 2H₂O

4. Aniline forms azodye with benzene diazonium chloride but benzyl amine does not.

5. Aniline being a primary amine gives carbylamine test while N-methylaniline being a 2° amine does not answer carbylamine test.

Question 9.
Write short notes on the following:

1. Carbylamine reaction.
2. Hoffman’s bromamide reaction.

Answer:
1. Methyl amine is a 1° amine and so it gives the carbylamine test. When methylamine is warmed with chloroform and alcoholic solution of KOH, foul smelling methyl isocyanide is formed.

Dimethyl amine is a 2° amine and hence it does not answer carbylamine test. Or they can be distinguished by Hinsberg’stest.

2. When an acid amide is heated with Br₂ and an aqueous or ethanolic solution of alkali, a primary amine containing one carbon less than the initial amide is obtained. This is called Hoffmann’s bromamide degradation reaction.

Question 10.
Write the IUPAC names of the following compounds and classify them into primary, secondary and tertiary amines.

1. (CH₃)₂CHNH₂
2. CH₃(CH₂)₂NH₂
3. CH₃NHCH(CH₃)₂
4. (CH₃)₃CNH₂

Answer:

1. Propan-2-amine (1° amine)
2. Propan-1-amine (1° amine)
3. N-Methylpropan-2-amine (2° amine)
4. 2-Methylpropan-2-amine (1° amine)

Question 11.
Account for the following:

1. pK_b of aniline is more than that of methylamine.
2. Ethylamine is soluble in water whereas aniline is not.

Answer:

1. In CH₃– NH₂, the +l effect of methyl group increases the electron density around N atom and it increases the electron releasing tendency of the molecule. In C₆H₅ – NH₂ the resonance effect causes delocalisation of lone pair over the ring and thereby decreases its basic strength. Since aniline is less basic than methylamine, its pKb value is greater than that of CH₃NH₂.

2. Solubility of ethylamine in water is attributed to its ability to form hydrogen bonds with water molecules. In aniline the non-polar hydrocarbon part (the ring skeleton) is relatively larger and therefore, has no interactions with polar water molecules. It also decreases the tendency of hydrogen bonding with water molecules. Hence, aniline is not soluble in water.

Question 12.
Account for the following:

1. Methylamine in water reacts with ferric chloride to precipitate hydrated ferric oxide.
2. Although amino group is o- and p- directing in anomatic electrophilic substitution reactions, aniline on nitration gives a substantial amount of m-nitroaniline.

Answer:
1. Methyl amine, being more basic than water exists in water as N-methylammonium hydroxide which reacts with ferric chloride to form hydrated ferric oxide.

2. Aniline being a base mostly gets protonated in the presence of acids to form anilinium ions (NH₃⁺). For electrophlic ring substitution, – NH₂ group is activating and ortho and para directing whereas – NH₃⁺ is deactivating and meta directing. In aniline, the probability of NO₂⁺ attack at para position is relatively more because of steric hinderance at ortho position. Anilinium ion, the attack of NO₃⁺ mostly occurs at meta position.

Question 13.
Account for the following:

1. Aniline does not undergo Friedel-Crafts reaction.
2. Diazonium salts of aromatic amines are more stable than those of aliphatic amines.

Answer:
1. Aniline is a base due to electron donating nature of lone pair on N atom of -NH₂ goup. Aniline therefore, forms salt with AICI₃ which is Lweis acid and a catalyst used in Friedel Craft’s reaction.

So the catalyst will not be available to produce electrophile.

2. Arenediazonium ion is resonance stabilised whereas no resonance stabilisation occurs in alkyl diazonium ion.

Plus Two Chemistry Amines NCERT Questions and Answers

Question 1.
Write the IUPAC names of the following compounds and classify them into primary, secondary and tertiary amines.

1. (CH₃)₂CHNH₂
2. CH₃(CH₂)₂NH₂
3. CH₃NHCH(CH₃)₂
4. (CH₃)₃CNH₂
5. C₆H₅NHCH₃
6. (CH₃CH₂)₂NCH₃
7. m-BrC₆H₄NH₂

Answer:

1. Propan-2-amine (1° amine)
2. Propan-1-amine (1° amine)
3. N-Methylpropan-2-amine (2° amine)
4. 2-Methylpropan-2-amine (1° amine)
5. N-Methylbenzenamine (2° amine)
6. N-Ethyl-N-methylethanamine (3° amine)
7. 3-Bromobenzenamine (1° amine)

Question 2.
Give one chemical test to distinguish between the following pairs of compounds.

1. Methylamine and dimethylamine
2. Secondary and tertiary amines
3. Ethylamine and aniline
4. Aniline and benzylamine
5. Aniline and N-methylaniline

Answer:
1. Methyl amine is a 1° amine and so it gives the carbylamine test. When methylamine is warmed with chloroform and alcoholic solution of KOH, foul smelling methyl isocyanide is formed.

Dimethyl amine is a 2° amine and hence it does not answer carbylamine test. Or they can be distinguished by Hinsberg’stest.

2. Secondary and tertiary amines can be distinguished by Hinsberg’stest.

Secondary amines react with Hinsberg’s reagent (benzene sulphonyl chloride) to form N, N- dialkyl benzene sulphonamide which is insoluble in alkali.
Tertiary amines do not react with Hinsberg’s reagent.

3. Ethyl amine is an aliphatic 1° amine. When treated with HNO₂ (NaNO₂ and HCI) it forms ethanol with liberation of N₃ gas.

Aniline is an aromatic 1° amine. When treated with HNO₂ at low temperature (273 – 278 K) it gives benzene diazonium chloride which undergoes coupling reaction with phenol to form an orange azo dye.
C₆H₅NH₂ + HNO₃ + HCI → C₆H₅N₂⁺+Cl^– + 2H₂O

4. Aniline forms azodye with benzene diazonium chloride but benzyl amine does not.

5. Aniline being a primary amine gives carbylamine test while N-methylaniline being a 2° amine does not answer carbylamine test.

Question 3.
How will you convert:
(i) Ethanoic acid into methanamine
(ii) Hexanenitrile into 1-aminopentane
Answer:

Question 4.
How will you convert:
(i) Methanol to ethanoic acid
(ii) Ethanamine into
Answer:

Question 5.
How will you convert:
(i) Ethanoic acid into propanoic acid
(ii) Nitromethane into dimethylamine
Answer:

Question 6.
An aromatic compound ‘A’ on treatment with aqueous ammonia and heating forms compound ‘B’ which on heating with Br₂ and KOH forms a compound ‘C’ of molecular formula C₆H₇N. Write the structures and IUPAC names of compounds A, B, and C.
Answer:

Question 7.
Write short notes on the following:

1. Carbylamine reaction
2. Diazotisation
3. Hoffmann’s bromamide reaction
4. Coupling reaction
5. Gabriel phthalimide synthesis.

Answer:
1. Carbylamine reaction
Primary amines (both aliphatic and aromatic) when heated with chloroform and ethanolic potassium hydroxide form isocyanides (also known as carbylamines) which have a foul smell. This reaction is called carbylamine reaction and is used as a test for primary amines. Secondary and tertiary amines do not show this reaction.

2. Diazotisation:
Aromatic amines react with nitrous acid (HNO₂) at low temperature (273-278 K) to form diazonium salts. The process is known as diazotisation eg.

3. Hofmann’s bromamide reaction:
In this reaction, an acid amide is heated with Br₂ and aq. NaOH when 1° amine having one carbon atom less is produced. This involves migration of alkyl or aryl group from carboxyl carbon of the amide to nitrogen atom of the amine. The amine so formed contains one carbon less than that present in amide.

4. Coupling reaction:
Diazonium salts react with phenol and amines to give azo compounds which have an extended conjugate system having both the aromatic rings joined by -N = N – bond. eg.

5. Gabriel phthalimide synthesis:
This method is used for preparing only 1° amines. In this method, phthalimide is treated with alcoholic KOH to give potassium phthalimide, which is treated with alkyl halide or benzyl halide to form N- alkyl or aryl phthalimide. The hydrolysis of N- alkyl phthalimide with 20% HCI under pres¬sure or refluxing with NaOH gives 1° amines.


The more convenient method is by the treatment of alkyl phthalimide with hydrazene.

Phthalic acid can again be converted into phthalimide and is used again and again. This method is very useful because it gives pure amines.

Question 8.
Give plausible explanation for each of the following:

1. Why are amines less acidic than alcohols of comparable molecular masses?
2. Why are primary amines higher boiling than tertiary amines?
3. Why are aliphatic amines stronger bases than aromatic amines?

Answer:
1. Loss of proton from amines give amide ion whereas loss of a proton from alcohol gives an alkoxide ion.

Since O is more electronegative than N, therefore, RO^– can accomodate the -ve charge more eaisly than RNH^–. Consequently, RO^– is more stable than RNH^–. Thus, alcohols are more acidic than amines.

2. Primary amines (RNH₂) have two hydrogen atoms on the N atoms and therefore, form intermolecular hydrogen bonding

Tertiary amines (R₃N) do not have hydrogen atoms on the N atom and therefore, these do not form hydrogen bonding in primary amines, they have higher boiling points than tertiary amines of comparable molecular mass. For example, boiling point of n-butylamine is 351 K while that of tert-butylamine is 319K.

3. Both arylamines and alkalamines are basic in nature due to the presence of lone pair on N-atom. But arylamines are less basic than alkyamines. For example, aniline is less basic than ethylamine as shown by K_b values:
Ethylamine: K_b = 4.7 × 10^-4
Aniline: K_b =4.2 × 10^-10

The less basic character of aniline can be explained on the basis of aromatic ring present in aniline. Aniline can have the following resonating structures:

It is clear from the above resonating structures that three of these (II, III and IV) acquire some positive charge on N atom. As a result, the pair of electrons become less available for protonation. Hence, aniline is less basic than ethyl amine in which there is no such resonance.

Students can Download Chapter 3 Current Electricity Questions and Answers, Plus Two Physics Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus Two Physics Chapter Wise Questions and Answers Chapter 3 Current Electricity

Plus Two Physics Current Electricity NCERT Text Book Questions and Answers

Question 1.
A storage battery of a car has an e.m.f. of 12V. If the internal resistance of the battery is 0.4W, what is the maximum current that can be drawn from the battery?
Answer:
E = 12 V, r = 0.4Ω, I = ?
Since I = \(\frac{E}{r}=\frac{12}{0.4}\) = 30A.

Question 2.
A battery of e.m.f. 10V and internal resistance 3W is connected to a resistor. If the current in the circuit is 0.5A, what is the resistance of the resistor? What is the terminal voltage of the battery when the circuit is closed?
Answer:
Given E = 10V, r=3?, I = 0.5, R = ?
Since V = E – Ir
or V= 10 – 0.5 × 3
or V = 8.5 volt
And R = \(\frac{V}{I}=\frac{8.5}{0.5}\) = 17A.

Question 3.

1. Three resistors 1W, 2W and 3W are combined in series. What is the total resistance of the combination?
2. If the combination is connected to a battery of e.m.f. 12V and negligible internal resistance, obtain the potential drop across each resistor:

Answer:
Given

R₁ = 1Ω, R₂ = 2Ω , R₃= 3Ω
1. Total resistance of series combination
R = R₁ + R₂ + R₃
or R – 1 + 2 + 3 = 6Ω.

2. Since V=IR
I = \(\frac{V}{R}=\frac{12}{6}\)
∴ V₁ = IR₁ = 2 × 1 = 2V
V₂ = IR₂ = 2 × 2 = 4V
V₃ = IR₃ = 2 × 3 = 6V.

Question 4.
A silver wire has a resistance of 2.1W at 27.5°c, and a resistance of 2.7W at 100°C. Determine the temperature coefficient of resistivity of silver.
Answer:
R_t1 = R_27.5 = 2.1Ω and
R_t2 = R₁₀₀ = 2.7Ω
Applying the relation

a = 0.0039°C^-1

Question 5.
The number density of free electrons in a copper conductor estimated is 8.5 × 10²⁸m^-3. How long does an electron take in drifting from one end of a wire 3.0m long to its other end? The area of cross-section of the wire is 2.0 × 10^-6m² and it is carrying a current of 3.0A.
Answer:
n = 8.5 × 10²⁸m^-3; A = 2 × 10^-6m²
I – 3.0A; I = 3m
I = v_dneA
\(\frac{3}{t}=\frac{3}{8.5 \times 10 \times 1.6 \times 10 \times 2 \times 10}\)
t = 8.5 × 11²⁸ × 1 .6 × 10^-19 × 2 × 10^-6
= 27.2 × 10^-3sec.

Question 6.
Choose the correct alternative:

1. Alloys of metals usually have (greater/ less) resistivity than that of their constituent metals.
2. Alloys usually have much (lower/higher) temperature coefficients of resistance than pure metals.
3. The resistivity of alloy manganin (is nearly indepent of/ increases rapidly) with increase of temperature.
4. The resistivity of a typical insulator (e.g. amber) is greater than that of a metal by a factor of the order of (10²²/10²³).

Answer:

1. Greater
2. lower
3. nearly independent of
4. 10²².

Plus Two Physics Current Electricity One Mark Questions and Answers

Question 1.
n equal resistors are first connected in series and then connected in parallel. What is the ratio of the maximum to the minimum resistance?
(a) n
(b) 1/n²
(c) n²
(d) 1/ n
Answer:
(c) n²
Explanation: In series R_s = nR
In parallel \(\frac{1}{Rp}\) = \(\frac{1}{R}\) + \(\frac{1}{R}\) ….n terms, Rp = \(\frac{R}{n}\)
∴ R_s/R_p = n²/1.

Question 2.
A car battery of emf 12 V and internal resistance 5 × 10^-2Ω, receives a current of 60 amp, from external source, then potential difference of battery is.
(a) 12V
(b) 9V
(c) 15V
(d) 20 V
Answer:
(c) 15V
When cell is changed by an external source, terminal voltage, V = E + Ir
V= 12 + 60 × 5 × 10^-2
=15.

Question 3.
A flowing of 10⁷ electron persecond in a conducting wire constitutes a current of……….A
(a) 1.6 × 10^-12
(b) 1.6 × 10²⁶
(c) 1.6 × 10^-26
(d) 1.6 × 10¹²
Answer:
(a) 1.6 × 10^-12
Flow of electrons \(\frac{n}{t}\) = 10⁷/sec.
There fore, Current (I) = \(\frac{q}{t}\) = \(\frac{ne}{t}\) = \(\frac{n}{t}\) × e
= 10⁷ × (1.6 × 10^-19)
= 1.6 × 10^-12 A.

Question 4.
Copper and silicon is cooled from 300K to 60K, the specific resistance.
(a) decrease in copper but increase in silicon
(b) increase in copper but decrease in silicon
(c) increase in both
(d) decrease in both
Answer:
(a) decrease in copper but increase in silicon.

Question 5.
State the potentiometer principle.
Answer:
Potential difference between two points of a current carrying conductor is directly proportional to the length of the wire between two points.

Question 6.
Find the current following through the network shown in the figure

Answer:
Since given circuit is in the form of Wheatstone bridge,

Question 7.
Kirchhoff’s first and second laws of electrical circuits are consequences of……(1)….and…..(2).. respectively
Answer:

• Conservation of electric charge
• Energy respectively

Question 8.
Pick the odd one out the following.
(a) Ohm’s law
(b) Lenz’slaw
(c) Coulomb’s law
(d) Gauss’s law
(e) Energy conservation law
Answer:
(a) Ohm’s law (It is not a universal law).

Question 9.
“Ohms law is not a fundamental law” Comment on this.
Answer:
Ohms law is not a universal law because metals do not obey this law at high temperature. Moreover, certain materials (diode and transistors, etc.) does not obey ohms law.

Plus Two Physics Current Electricity Two Mark Questions and Answers

Question 1.
Figure below shows a diagram of a water circuit. In many ways it behaves like an electric circuit. Draw an equivalent electric circuit. (Hint – water-wheel can be replaced by motor)

Answer:

Question 2.
A, B, C, and D are four rings on a carbon resistor. A = yellow, B = violet, C = Yellow, D, Silver

1. What is the value of resistance of above resistor?
2. The combined resistance of the above two resistor is

• 120Ω
• 45Ω
• 165Ω
• 35Ω

Answer:
1. 47 × 10⁴ ± 10%.

2. 12 × 10¹ + 45 × 10°
120 + 45 = 165Ω.

Question 3.
A = Brown B = Black C= Red D= Gold

1. What is the value of resistance without considering variation?
2. If the fourth ring is silver coloured what will be the change in accuracy?

Answer:

1. 1000Ω ± 5%
2. 10%

Question 4.
A junction of a electrical circuit is given below. Analyze the figure and answer the following

1. What is the value of I₁ and I₂?
2. State the law that can be applied to find I₁ and I₂?

Answer:
1. According Kirchoff first rule
3 + 2 = I + I₁
I₁ = 4A
I₁ = 3 +I₂
4 = 3 + I₂
I₂ = 1A

2. Total current meeting at any junction is zero.

Question 5.
The following question consists of two statements each, printed as assertion and reason. While answering these questions you should choose any one of the following responses.
Assertion: In a simple battery circuit, the point at the lowest potential is positive terminal of the battery. Reasons: The electrons flows from higher potential to lower potential.
(a) Both assertion and reason are true and the reason is a correct explanation of the assertion.
(b) Both assertion and reason are true but the reason is not a correct explanation of the assertion.
(c) Assertion is true but reason is false.
(d) Both assertion and reason are false.
Answer:
(d) Both assertion and reason are false.

Plus Two Physics Current Electricity Three Mark Questions and Answers

Question 1.
Match the following.

Answer:

Question 2.
Match the following.

Answer:

Question 3.
“When electric current is passed through a resistance wire, it get heated up”.

1. Name the law associated with this phenomenon.
2. What happens to the heat energy developed, if the current through the wire is doubled.

Answer:

1. Joules law of heating
2. Heat developed in the conductor H = 1²R If current is doubled, Heat developed becomes 4 times.

Question 4.

1. Name the pd between terminals of the cell when

• key K is open
• K is closed

2. What is the reason for the difference in potential in the above two cases?
Answer:
1. key K is open

• e.m.f
• voltage.

2. Emf in a circuit
E = Ir + V
When key is open, I = 0
∴ E = V
When key is closed I ? 0
∴ V = E – Ir.

Question 5.
The variation of resistivity (ρ) with temperature (T) of a conductor, semiconductor and super conductor are given in the figure.

1. Identify them from the graph. (1)
2. Identify the figure in which the temperature coefficient of resistance of the material is positive. (1)
3. Write the equation connecting resistivity of the material with relaxation time. (1)

Answer:
1. From the graph:

• Fig (i) – Conductor
• Fig (ii) – Superconductor
• Fig (iii) – Semiconductor

2. Fig(i)

3. We have resistivity (ρ) from equation.
ρ = \(\frac{m}{n e^{2} \tau}\), where t is the relaxation time, m mass of electron, n number density of electron and e charge of electron.

Question 6.
When an animal touches an ‘electric-fence’ the animal gets a shock by completing an electrical circuit.

1. Draw an equivalent circuit using symbols, which shows the completed electrical circuit. (Assume that the animal has a resistance)
2. How much charge passes through the animal, if it receives a current pulse of 20mA for 0.1 seconds.
3. When a bird perches on the electric fence, the bird will not get a shock. Why?

Answer:
1.

2. 1 = Q/t
Q = 1 × t = 20 × 10^-3 × 0.1 = 20 × 10^-4C

3. Since the bird does not come in contact with the earth, its body is at same potential. So there is no potential difference and current. Hence the bird will not get a shock.

Question 7.
1. Pd between terminals when k is open is called

• emf
• lost voltage
• terminal voltage
• induced voltage

2. Give an equation connecting R, r, I and E What is the value of E for open circuit and ideal cell.

3. What happens to terminal voltage if current increases

• for an ideal cell
• for an ordinary cell.

Answer:
1. e.m.f

2. E = I(r+R).

3. For ideal cell, internal resistance is zero. Hence E = v. ie. terminal voltage does not change with current.
For ordinary cell, when current increases, V decreases.

Question 8.

1. What is the current through this circuit?
2. What is p.d. across 2Ω and 3Ω?
3. What is potential at A?
4. What is potential at B?

Answer:
1. Current I = \(\frac{\text { total voltage }}{\text { total resistance }}\)
I = \(\frac{5}{2+3}\) = 1A

2. Voltage across 2Ω
V = 1 × 2
V₂ = 2 V
Voltage across 3Ω
V = 1 × 3 = 3V

3. 5V

4. 3V

Question 9.
The relation between Voltage V (across the conductor) and current I through the conductor is given in the graph.

1. Which law establishes the relation between voltage and current?
2. A metal wire of resistivity 6.4 × 10^-5 ohm-cm and length 1.98 m has a resistance of 7Ω. Find radius of wire

Answer:
1. Ohms law

2. Resistance of wire R = \(\frac{ρl}{A}\)

= 2 × 10^-3m.

Question 10.
A circuit diagram of an instrument is given below.

1. Identify the instrument and state the principle of this instrument
2. Modify the circuit diagram to compare the emf of two cells.
3. How can increase the sensitivity of this instrument?

Answer:
1. Potentio meter

2. Comparison of e.m.f of two cells using potentiometer

a. Principle:
Potential difference between two points of a current carrying conductor (having uniform thickness) is directly proportional to the length of the wire between two points.

b. Circuit details :
A battery (B₁), Rheostat and key are connected in between A and B. This circuit is called primary circuit. Positive end of E₁ and E₂ are connected to A and other ends are connected to a two way key. Jockey is connected to a two key through galvanometer. This circuit is called secondary circuit.

c. Working and theory :
Key in primary circuit is closed and then E₁ is put into the circuit and balancing length l₁ is found out.
Then E_1∝ l₁ …………(1)
Similarly E₂ is put into the circuit and balancing length (l₂) is found out.
Then, E_{2 ∝} l₂ (2)
Dividing Eq(1)byEq(2),
\(\frac{E_{1}}{E_{2}}=\frac{l_{1}}{l_{2}}\)………..(3)

3. Increase the length of potentio meter wire.

Question 11.
A long resistance wire is stretched between two iron nails. A battery of 2V is applied across the wire. One end of a torch bulb is connected to nail and other end is made in contact as shown in figure.
1. If this wire slides over the resistance wire from nail 1 to nail 2, what happens to the brightness of the bulb.

• Increases
• Decreases
• Remains constant
• First increases then decreases.

2. How this principle is used to determine internal resistance of cell.

3. What happens to the reading, if we change 2V with 3V during the time of reading.

Answer:
1. Increases.

2. Measurement of internal resistance using potentiometer Principle:
[Same as before]
a. Circuit details :
Battery B₁ Rheostat and key K₁ are connected in between A and B. This circuit is called primary.

In the secondary circuit a battery E having internal resistance ‘r’ is connected. A resistance box (R) is connected across the battery through a key (K₂). Jockey is connected to battery through galvanometer.

b. Working and theory :
The key (K₁) in the primary circuit is closed and the key is the secondary (K₂) is open. Jockey is moved to get zero deflection in galvanometer. The balancing length l₁, (from A) is found out.
Then we can write.
E_1∝ l₁ ____(1)
Key K₂ is put in the circuit, corresponding balancing length (l₂) is found out. Let V be the applied voltage, then
V_{1 ∝} l₁ ____(2)
‘V’ is the voltage across resistance box. Current through resistance box ie, voltage across resistance,
V = \(\frac{E R}{(R+r)}\) _____(3)
Substituting eq (3) in eq (2),
\(\frac{E R}{(R+r)}\) _∝ l₂ ______(4)
Dividing eq (1) by eq (4),

r = \(\frac{\mathrm{R}\left(l_{1}-l_{2}\right)}{l_{2}}\)

3. Primary Voltage should not change while doing experiment. When we use 3v instead of 2v, potential gradient will change. Hence balancing length will change.

Question 12.
“Electric current has both direction and magnitude”

1. What is meant electric current
2. What is the conventional direction of electric current
3. Even though current has both magnitude and direction it is not a vector quantity. Why?
4. Thermal Motion of electrons in a conductor cannot constitute an electric current. Why?

Answer:

1. Rate of flow of charge is called current I = dq/dt
2. Direction of motion of positive charges
3. It does not obey vector law of addition
4. Average velocity of thermal motion is zero. Hence thermal motion does not produce current.

Question 13.
Match the following

Answer:

1. Metals – electrons
2. Semiconductors – electrons and holes
3. Superconductors – cooper pairs

Plus Two Physics Current Electricity Four Mark Questions and Answers

Question 1.
A cell arid two resistors R₁ and R₂ are provided to you.

1. Draw different combinations of resistors using R₁, R_2, and the cell.
2. Derive an expression for the effective resistance of the circuit in which current is the same in both resistors
3. lf R₁= 4Ω and R₂ = 6Ω, in which combination effective resistance is minimum? Find its value?

Answer:
1.

2. Derive an expression for effective resistance in series:
Consider three resistors R₁, R₂ and R₃ connected in series and a pd of V is applied across it.

In the circuit shown above the rate of flow of charge through each resistor will be same i.e. in series combination current through each resistor will be the same. However, the pd across each resistor are different and can be obtained using ohms law.
pd across the first resistor V₁ = I R₁
pd across the second resistor V₂ = I R₂
pd across the third resistor V₃ = I R₃
If V is the effective potential drop and R is the effective resistance then effective pd across the combination is
V = IR
Total pd across the combination = the sum pd across each resistor, V = V₁ + V₂ + V₃
Substituting the values of pds we get IR = IR₁ + IR₂ + IR₃
Eliminating I from all the terms on both sides we get
R = R₁ + R₂ + R₃ ………(1)
Thus the effective resistance of series combination of a number of resistors is equal to the sum of resistances of individual resistors.

3. The effective resistance becomes minimum in parallel connection.

R = 2.4Ω.

Question 2.
1. State whether the following statement is true or false “The value of resistance of a metal increase with the rise of temperature”.

2. Explain the reason.

3. With the help of the graph, match the following

4. Alloys like manganin, eureka, constantan, etc. are used in making standard resistance coils. Why?
Answer:
1. True.

2. When temperature increases, the amplitude of vibration of atom increases. Hence relaxation time decreases. Hence resistivity of metal increases according to the equation

3.
A_____Carbon
B_____Manganin
C_____Iron.

4. The temperature coefficient of resistance of manganin, eureka and constantan, etc are zero. Hence they are used in making standard resistance coils.

Question 3.

1. Identify the above device and give the principle behind it.

2. Obtain the mathematical condition for the galvanometer current to be zero.

3. If the balancing length T obtained fora resistance wire in the arrangement is 40cm. Find the new balancing length if the same resistance wire is folded to half its length and connected to the same gap.
Answer:
1. Meter bridge.

2. We get galvanometer current as zero, when P/Q = R/S. For derivation of P/Q=R/S
Wheatstone’s Bridge:
Four resistances P, Q, R, and S are connected as shown in figure. Voltage ‘V’ is applied in between A and C. Let I₁, I₂, I₃ and I₄ be the four currents passing through P, R, Q, and S respectively.

Working:
The voltage across R
When key is closed, current flows in different branches as shown in figure. Under this situation
The voltage across P, V_AB = I₁P
The voltage across Q, V_BC = I₃Q ……(1)
The voltage across R, V_AD = I₂R
The voltage across S, V_DC = I₁S
The value of R is adjusted to get zero deflection in galvanometer. Under this condition,
I₁ = I₃ and I₂ = I₄……(2)
Using Kirchoff’s second law in loopABDA and BCDB, weget
V_AB = V_AD ……….(3)
and V_BC = V_DC …….. (4)
Substituting the values from eq(1) into (3) and (4), we get
I₁P = I₂R……….(5)
and I₃Q = I₄S……..(6)
Dividing Eq(5) by Eq(6)
\(\frac{I_{1} P}{I_{3} Q}=\frac{I_{2} R}{I_{4} S}\)
\(\frac{P}{Q}=\frac{R}{S}\) [since I₁ = I₃ and I₂ = I₄]
This is called Wheatstone condition.

3. When we apply this condition in meter bridge, we get

If wire is folded, New resistance x₁ = \(\frac{x}{2}\)
Substituting this in P/Q = R/S we get

Question 4.
1. Potentiometer is better than voltmeter for measuring emf because

• It is cheap
• Easy to handle
• Its measurement uses null method

2. Give the basic principle of potentiometer,

3.

If K₂ is open balancing length is 600cm, if K₂ is closed 350cm is balancing length. Calculate the internal resistance.

Answer:
1. Its measurement uses null method.

2. Principle:
Potential difference between two points of a current carrying conductor (having uniform thickness) is directly proportional to the length of the wire between two points.

3. I = 600cm, I = 350 cm

Question 5.
Under an external electric field electrons drift slowly inside the conductor.
1. The velocity of drift is

• 1 mm/s
• 10⁵ m/s
• 3 × 10⁸ m/s
• 3 × 10⁹ m/s

2. What is meant by relaxation time?

3. Write an expression for drift velocity in terms of relaxation time.

4. When temperature increases what happens to drift velocity?
Answer:
1. 1mm/s.

2. The average time between two successive collision is called relaxation time.

3. V_d = \(\frac{\mathrm{eE}}{\mathrm{m}}\) t

4. We know drift velocity
V_d = \(\frac{\mathrm{eE}}{\mathrm{m}}\) t
When temperature increases, relaxation time decreases. As a result drift velocity decreases.

Question 6.
1. State whether the following statement is correct. “If the current through the cell is from its positve to negative, against the direction of emf, then the potential drop across the internal resistance aids the emf of the cell. (1)

2. You are given two cells. Group them so that they give more voltage. Arrive at the expression for effective emf and internal resistance. (3)
Answer:
1. True. Internal resistance and lost volt always opposes current flow through the cell”.

2.

Considertwo cells in series. Let ε₁, r₁ be the emf and internal resistance of first cell. Similarly ε₂, r₂ be the emf and internal resistance of second cell. Let I be the current in this circuit.

From the figure, the P.d between A and B
V_A – V_B = ε₁ – 1 ………(1)
Similarly P.d between B and C
V_B – V_C = ε₂ – 1 ……..(2)
Hence, P.d between the terminals Aand C
V_AC = V_A – V_C = V_A – V_B + V_B – V_C
V_AC = [V_A – V_B] + [V_B – V_C]
when we substitute eqn. (1) and (2) in the above equation.
V_AC = ε₁ – Ir₁ + ε₂ – Ir₂
V_AC = (ε₁ – ε₂) – I(r₁ + r₂)
V_AC = ε_eq – Ir_eq
where ε_eq = ε₁ + ε₂, and r_eq = r₁ + r₂

Question 7.
The resistance value of a conductor depends on its physical dimensions.
1. Give the expression for resistance of a conductor in terms of its physical dimension.

2.

(l length and d diameter) A potential V is applied between the ends of two conductor of same material shown in the figure.

• Express the resistance of the second conductor in terms of the resistance of the first conductor. (1)
• Find the ratio of electric field across the two conductors.

Answer:
1. R = ρ \(\frac{1}{A}\)
l – length of the conductor and
A – Area of cross section

2.
a.

b.

Question 8.
Three resistors R₁, R₂, R₃ are to be combined as shown in the figure.

1. Identify the series and parallel combinations. (1)
2. Which combination has lowest resistance. Arrive at the expression for the effective resistance of this combination. (3)

Answer:
1. Fig(i) – parallel Fig. (ii) – series

2. Fig. (i)
Let V be the potential between A and B.

I = I₁ + I₂ + I₃
and applying Ohm’s law to R₁, R₂ and R₃ we get,
V= I₁R₁,V=I₂R₂,V=I₃R₃
So that
I = I₁ + I₂ + I₃ = V\(\left(\frac{1}{R_{1}}+\frac{1}{R_{2}}+\frac{1}{R_{3}}\right)\)
An equivalent resistance R_eq that replace the combination, and hence

Question 9.
An electric circuit is given in the Figure.

The potential difference between A and D is 40V.

1. Find the effective resistance between A and D in terms of R. (1)
2. Calculate the potential difference between A and O.

Answer:
1.

2. V_AD = V_AO + V_OD
But V_OD = 3V_AO
∴ V_AD = V_AO + 3V_AO
40 = 4V_AO
V_AO = \(\frac{40}{4}\) = 10V.

Plus Two Physics Current Electricity Five Mark Questions and Answers

Question 1.
Resistance are used to reduce the current flow in a circuit.
1. A carbon resistor has coloured strip and shown in the figure. What is its resistance?

2. Resistance can be connected in series and parallel to obtain the required value of resistance. Derive an expression for the effective resistance when three resistors are connected in parallel.

3. Kirchhoff’s rules are used to analyses the electric circuit. Use it to analyze the Wheatstone Bridge and arrive at Wheatstone’s condition for balancing the bridge.
Answer:
1. blue, Gray, yellow, gold
1st – Blue – 6
IInd – Gray – 8
IIIrd – Yellow – 10⁴
Iv – gold – 5%
68 × 10⁴ ± 5%.

2. Derive an expression for effective resistance in series:
Consider three resistors R₁, R₂ and R₃ connected in series and a pd of V is applied across it.

In the circuit shown above the rate of flow of charge through each resistor will be same i.e. in series combination current through each resistor will be the same. However the pd across each resistor are different and can be obtained using ohms law.
pd across the first resistor V₁ = I R₁
pd across the second resistor V₂ = I R₂
pd across the third resistor V₃ = I R₃
If V is the effective potential drop and R is the effective resistance then effective pd across the combination is
V = IR
Total pd across the combination = the sum pd across each resistor, V = V₁ + V₂ + V₃
Substituting the values of pds we get IR = IR₁ + IR₂ + IR₃
Eliminating I from all the terms on both sides we get
R = R₁ + R₂ + R₃ ………(1)
Thus the effective resistance of series combination of a number of resistors is equal to the sum of resistances of individual resistors.

3. Wheatstone’s Bridge:
Four resistances P,Q,R and S are connected as shown in figure. Voltage ‘V’ is applied in between A and C. Let I₁, I₂, I₃ and I₄ be the four currents passing through P,R,Q and S respectively.

Working:
The voltage across R
When key is closed, current flows in different branches as shown in figure. Under this situation
The voltage across P, V_AB = I₁P
The voltage across Q, V_BC = I₃Q ……(1)
The voltage across R, V_AD = I₂R
The voltage across S, V_DC = I₁S
The value of R is adjusted to get zero deflection in galvanometer. Under this condition,
I₁ = I₃ and I₂ = I₄……(2)
Using Kirchoff’s second law in loopABDA and BCDB, weget
V_AB = V_AD ……….(3)
and V_BC = V_DC …….. (4)
Substituting the values from eq(1) into (3) and (4), we get
I₁P = I₂R……….(5)
and I₃Q = I₄S……..(6)
Dividing Eq(5) by Eq(6)
\(\frac{I_{1} P}{I_{3} Q}=\frac{I_{2} R}{I_{4} S}\)
\(\frac{P}{Q}=\frac{R}{S}\) [since I₁ = I₃ and I₂ = I₄]
This is called Wheatstone condition.

Question 2.
A rectangular conductor of length I and area of cross section A and electron density n; is shown below.

1. When the face Y is given positive potential and X negative potential what will happen to the electrons inside the block
2. What is meant by drift velocity? How is it related to the field inside the metal?
3. Deduce an expression connecting intensity of electric field and drift velocity.
4. Under the application of an electric field do all the electrons move in a same direction? Explain

Answer:
1. Electrons will be accelerated towards the side Y.

2. Drift Velocity (v_d):
The average velocity acquired by an electron under the applied electric field is called drift velocity.
Explanation :
When a voltage is applied across a conductor, an electric filed is developed. Due to this electric field electrons are accelerated. But while moving they collide with atoms, lose their energy and are slowed down. This acceleration and collision are repeated through the motion. Hence electrons move with a constant average velocity. This constant average velocity is called drift velocity.

3. Expression for drift velocity :
Let ‘V’ be the potential difference across the ends of a conductor. This potential difference makes an electric field E. Under the influence of electric field E, each free electron experiences a Coulomb force.
F = -eE
or ma = -eE
a = \(\frac{-e E}{m}\) ……….(1)
Due to this acceleration, the free electron acquires an additional velocity. A metal contains a large number of electrons.
For first electron, additional velocity acquired in a time τ,
v₁ = u₁ + aτ₁
where u₁ is the thermal velocity and τ is the relaxation time.
Similarly the net velocity of second, third……electron
v₂ = u₂ + aτ₂
v₃ = u₃ + aτ₃
v_n = u_n + aτ_n
∴ Average velocity of all the ‘n’ electrons will be

V_av = 0+ aτ (∴ average thermal velocity of electron is zero)
where

where V_av is the average velocity of electron under an external field. This average velocity is called drift velocity.
ie. drift velocity V_d = aτ……(2)
Substitute eq (1) in eq (2)
V_d = \(\frac{-e E}{m}\) τ

4. Electrons will continues its random thermal motion even in the presence of electric field.

Question 3.
To study the relation between potential difference and current in an electrical circuit, a student is provided with a resistance wire, a cell, and a key.
1. Draw a circuit which allows current flow through the resistance wire.

2. Modify the circuit by introducing an ammeter, Voltmeter and a rheostat for varying the potential difference across the resistance and to measure that potential difference and the corresponding current.

3. Let in the above experiment the student obtained the following data.

Draw a graph connecting V and I using above data. Then establish the relation between V and I as a law.

4. Instead of the resistance wire if the student uses a p-n junction diode in the forward biased condition how the relation between V and I changes? Justify.
Answer:
1.

2.

3.

The above graph shows that, current flowing through a conductor is directly proportional to potential difference across it ends.

4. The relation between V and I becomes nonlinear. Because, Pn diode does not obey ohms law.

Question 4.
In all metallic conductors, electric conduction is due to drifting of free electrons. But the resistivity of different metals are different.

1. Write the expression for resistivity of a conductor in terms of its dimensions.
2. Name the factors on which resistivity of a metal depends.
3. Arrive at an expression for electrical resistivity of a metal in terms of relaxation time.
4. Using the above expression explain the variation of resistivity with temperature.

Answer:
1. ρ = \(\frac{RA}{l}\).

2. Temperature and Nature of metal

3. We know current density
J = nv_de
But V_d = \(\frac{e E}{m}\) τ

4. When temperature increases, the amplitude of oscillation of atom increases. This will decrease . the relaxation time and hence resistivity increases.

Question 5.
You are supplied with a 1m long uniform resistance wire of resistance 3Ω and a cell of emf 1.5v.

1. Can you construct a potentiometer using 1m wire? If no, give reason; if yes, what is the least count of the arrangement?
2. Draw the connection diagram to compare the emf of Leclanche cell and Daniel cell using this arrangement.
3. How can you modify above arrangement to measure a p.d. in the range 0-1 mV with a least count of 0.15m V.

Answer:

1. Yes, LC is 1.5mV

2.

3. To get least count of 0.15mV, 10m wire has to be used.

Question 6.
A circuit diagram is given below. Analyze the figure and answer the following questions.

1. The above circuit is a modification of……..
2. What is the value of balancing length?
3. If 1.5 V cell is replaced by a 3V cell what will be the balancing length?
4. Calculate the value of X.

Answer:
1. Wheatstone bridge.

2. 100-20=80cm

3. No change in balancing length

4. P/Q = R/S
ie X/5 = 80/20
x = 80/20 × 5 = 20Ω.

Question 7.

1. Define electric power. What is its SI unit? (2)
2. Two bulbs of 50W, 220V and 100W, 220V are given. How will you connect the bulbs so that 50W, 220V bulb will glow brighter than 100W, 220V bulb. (1)
3. When the bulb 50W, 220V is connected to an 110V supply calculate the power generated. (2)

Answer:
1. The energy dissipated per unit time is the power.
P = \(\frac{\Delta \mathrm{W}}{\Delta \mathrm{t}}\)
P = IV =I²R = \(\frac{V^{2}}{R}\)
Unit is watt.

2. In series

3.

Question 8.
The figure shows the diagram of a potentiometer.

1. Give the principle of a potentiometer. (1)

2. The length of AB is 3m and resistance per unit length of the potentiometer wire is 4Ω/m. If E₁ = 4V, R = 20Ω and E₂ = 1V find the length of the potentiometer wire that balance E₂. (3)

3. If E₂>E₁ can we get the null deflection in galvanometer. Give reason. (1)
Answer:
1. When a constant current is flowing through a wire having uniform area of cross section and uniform composition the potential difference across any length of the wire is directly proportional to its length.
V ∝ l.

2. The resistance of potentiometer
R_p = 4 × 3 = 12Ω
Current through the potentiometer

Potential across potentiometer wire
V_AB = IR_p = 0.125 × 12 = 1.5V
Potential gradient k = \(\frac{V_{A B}}{I}=\frac{1.5}{3}\) = 0.5 V/m
Balancing length for cell E₂ is given from equation
E₂ = kI₂ = 0.5I₂

3. If E₂ > E₁, we will not get null deflection. The potential difference across the potentiometer wire AB should be higher than the emf of E₂.

Question 9.

1. When the switch is closed will all the bulbs glow? Give reason. (2)
2. Identify the underlying principle. Deduce the principle for a resistance network. (3)

Answer:
1. No. Since all the bulbs are identical the bridge is balanced. So potential B and C is same and no current flows through the bulb connected between B and C. So all other bulbs except R₅ will glow.

2. Four resistances P, Q, R, and S are connected as shown in figure. Voltage ‘V’ is applied in between A and C. Let I₁, I₂, I₃, and I₄ be the four currents passing through P, R, Q, and S respectively.

Students can Download Chapter 1 Introduction Microeconomics Questions and Answers, Plus Two Economics Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus Two Economics Chapter Wise Questions and Answers Chapter 1 Introduction Microeconomics

Plus Two Economics Introduction Microeconomics One Mark Questions and Answers

Question 1.
The diagram shows:
(a) A movement from ‘a’ to ‘b’ has no opportunity cost.
(b) A movement from ‘f’ to ‘b’ has an opportunity cost.
(c) Higher is the production of good 2 greater is the opportunity cost of reducing its production.
(d) Higher is the production of good 2 lesser is the opportunity cost of reaching its output.

Answer:
The concave shape of PPC shows that higher the production of goods 1 and 2. Goods 2 higher will be the opportunity cost of reducing production.

Question 2.
State economic terms. The allocations of scarce resources and the distribution of the final goods and services.
Answer:
The central problem of an economy.

Question 3.
As a result of liberalisation policy, the inflow of foreign capital has increased. What is its impact on production possibility frontier?
Answer:
PPC shifts upward as a result of the increase in the availability of capital resources.

Question 4.
What is the shape of a production possibility curve?
(i) Convex to origin
(ii) Concave to origin
(iii) Horizontal
(iv) Vertical
Answer:
(ii) Concave to origin

Question 5.
How does a market economy solve central economic problems?
(i) Central planning
(ii) Price mechanism
(iii) Both (i) and (ii)
(iv) None of the above
Answer:
(ii) Price mechanism

Question 6.
Scarcity definition was given by:
Answer:
(i) Adam Smith
(ii) Alfred Marshall
(iii) Lionel Robbins
(iv) Samuelson
Answer:
(iii) Lionel Robbins

Plus Two Economics Introduction Microeconomics Two Mark Questions and Answers

Question 1.
Fill in the blanks.

Answer:

Question 2.
Classify the following statement into two branches of economics.

1. Indian economy grew by 9.2% GDP in the financial year 2006.
2. An unexpected lorry strike caused the price of vegetables to rise.
3. Recently the RBI reduced the Cash Reserve Ratio to 5.5%.
4. Madras Cement LTD is planning to add 40 lakh tonne to its existing production capacity of 60 lakh tonnes.

Answer:

1. Macroeconomics
2. Microeconomics
3. Macroeconomics
4. Microeconomics

Question 3.
Distinguish between centrally planned economy and a market economy.
Answer:
In a centrally planned economy, the government or the central authority plan all the important activities in the economy. All important decisions regarding production, exchange, and consumption of goods and services are made by the government.

On the other hand in a market economy, all the important decisions are made on the basis of demand and supply conditions. The central problems regarding what and how much to produce are solved through the coordination of economic activities brought about by the price signals.

Question 4.
Give two examples of underutilization of resources.
Answer:

1. Improper distribution of scarce resources leads to underutilisation of capacities,
2. Due to technological backwardness, industrial workers’ capacity is underutilized.

Question 5.
Give a few examples of resources in economics.
Answer:
By the term ‘resources’, we mean land, labour, tools, machinery, etc. in economics.

Question 6.
The government should increase tax on tobacco products. Explain whether the statement is positive or normative.
Answer:
This is a normative statement because it says how the government should tax. It is only an opinion. This cannot be proved. Since it contains a value judgment it is a normative statement.

Question 7.
“Study of aggregates is equally important to study individual units.”
Substantiate the above statement by distinguishing the two branches of Economics. Give two examples for each.
Answer:

1. Microeconomics which is the study of individual units is helpful in analysing a micro-economy, whereas macroeconomics is helpful in under-standing the working of macroeconomy.
2. Microeconomics – Individual income, price of apple Macroeconomics – Inflation, national income.

Plus Two Economics Introduction Microeconomics Three Mark Questions and Answers

Question 1.
Classify the following into Microeconomics and Macroeconomics.
Answer:
Demand analysis, Consumption function, Theory of international trade, Income determination, Pricing of factors of production, Investment function.

Question 2.
Match Column B and C With Column A.

Answer:

Question 3.
“Since resources are limited, they should be properly used”. Comment on this statement in the light of utilization of energy resources in Kerala.
Answer:
This statement relates to the problem of scarcity of resources and thus connected to the scarcity definition of Lionel Robbins. According to this statement, the scarcity of resources forces the economy to choose the most urgent need that is to be satisfied.

Since energy resource in Kerala is limited in supply, it has to be judiciously utilized. Control over the utilization of energy is necessary in states like Kerala so that this scarce resource can be protected.

Question 4.
Classify the following features under the title centrally planned economy and market economy. Price mechanism, comprehensive planning, welfare motive, profit motive, public sector, private sector.
Answer:

Question 5.
“Labour intensive technique is the best technique of production”. Give arguments in favour of and against this statement.
Answer:
Arguments in favour of:

1. Labour intensive technique provides more employment opportunities.
2. Labour intensive technique needs less capital.
3. Labour intensive technique requires less skill only.

Arguments against:

1. Labour intensive technique is less productive.
2. Labour intensive technique prevents development
3. Labour intensive technique makes the economy less productive.

Question 6.
Given below a Production Possibility Curve of an economy. Compare the points in the context of production possibilities of the economy.

Answer:
The Production Possibility Curve is an analytical tool presenting the alternative production possibilities of an economy. It is used to explain the central problems of an economy and how they are solved.
In the diagram:
1. Point A indicates the efficient utilization of available resources.

2. Point B shows that the available resources of the economy are not fully utilized. In other words, it is an indication of the underutilization of resources.

3. Point C is outside the Production Possibility frontier. This means that the economy cannot produce at this point using the available resources.

Question 7.
Suppose there is growth of resources in an economy. How does it affect the PPC?
Answer:
When there is growth of resources the PPC shifts outwards as shown, below.

The PPC shifts from PP to P due to growth of resources in the economy. Therefore, economy produces more of food and cloth.

Question 8.
With the ₹500 cash award received by a student prepares a list of goods. She writes to have each of the goods priced @₹500.

1. An Economics textbook.
2. A movie with her friends.
3. An outing.
4. A dinner with her parents.

Explain opportunity cost. Identify the opportunity cost of buying one economic textbook.
Answer:
Opportunity cost is the next best alternative forgone. The opportunity cost of buying an economic textbook is the foregone movie with friends.

Question 9.
Different economic systems solve basic economic problems using different mechanisms. Complete the following table by writing the basic economic problems as well as the mechanisms used. Also, give one example for each economic system.

Answer:

Question 10.
Read the following statements and write the terms used in economics.
Answer:

1. The curve representing various combinations of any two goods the economy can produce with the available resources and technology.
2. An investigation in economics concerned with it is rather than what ought to be.
3. An economic system in which basic problems are solved through planning.

Answer:

1. PPC
2. Positive economics
3. Socialism

Plus Two Economics Introduction Microeconomics Five Mark Questions and Answers

Question 1.
Classify the following statements into positive and normative statements.

1. Statement I: India introduced a new economic policy in 1991.
2. Statement II: Globalization badly affected India’s agricultural sector.
3. Statement III: The number of people living below poverty line has to be reduced from the present level of 21%.
4. Statement IV: Mean, median and mode are the measures of central tendency.

Answer:

1. Statement I: positive statement
2. Statement II:normative statement
3. Statement III:normative statement
4. Statement IV:positive statement.

Question 2.
“The implementation of Vizhinjam project will shift our PPC rightward”. Suggest two points in favour and against this statement.
Answer:
A production Possibility Curve is an analytical tool presenting the alternative production possibilities of an economy.
Points in favour of:

1. Since the Vizhinjam project needs abundant skilled manpower, it would shift our PPC rightward.
2. Kerala has abundant skilled manpower. They will get more employment and hence ppc will shift rightward.

Points against:

1. The abundant skilled labour available in Kerala is lying unutilized only partially.
2. The project need not be a continuous success as it will badly affect environment.

Question 3.
Prepare a production possibility schedule showing constant marginal opportunity cost.
Answer:

It is clear from the tables that in each production possibility to increase the production of wheat by one tonne, 20 kgs of rubber have to be sacrificed. This shows that there is constant marginal opportunity cost operating in this case. In this case, the PPC of rubber and wheat becomes a straight line.

Question 4.
Differentiate between micro economics and macro economics.
Answer:

Question 5.
A few statements are given below. Classify them under two branches of economics.

1. RBI formulated its new monetary policy.
2. National Income recorded the highest growth last year.
3. Shyam purchased a new mobile phone.
4. Inflation adversely affects the fixed income of people.
5. Total Fixed Cost of a firm remains constant even if output increases.

Answer:

1. Macro economics
2. Macro economics
3. Microeconomics
4. Macroeconomics
5. Microeconomics

Plus Two Economics Introduction Microeconomics Eight Mark Questions and Answers

Question 1.
Suppose a country uses its entire resources to provide educational and health facilities required for the people. Given the resources, the country can provide various combinations of number of schools and hospitals as shown in the table below.

a. Define PPC and represent the above schedule on a diagram.

b. Suppose the country has already attained near-total literacy. If so, will the country prefer points on upper portion of PPC or points on the lower portion of PPC? Substantiate your answer.

c. Which mechanism will you advice to utilise the resources to provide more health facilities planning or market? Give reasons.
Answer:
a. Production Possibility Curve (PPC) is a graphical representation of all possible combinations of two goods or services that can be produced in an economy with given level of resources and technology. It is also known as production possibility frontier (PPF). The shape of PPC is concave to the origin.

b. Combination D. Because more resources will be spent for health and less on education.
c. Planning. Because only the government can ensure public services.

Question 2.
Prepare a seminar paper on “central problems of an economy.
Answer:
Respected teachers and dear friends,
The topic of my seminar paper is “central problems of an economy”. As we know the central problems arise due to the fact that the human wants are unlimited and the means to satisfy those wants are limited. In this seminar paper, I would like to present the central problems such as what to produce, how to produce and for whom to produce.

Introduction:
The resources available to the consumer are limited but their wants are unlimited. Due to scarcity of resources, the economy faces the problem of choice. It is this mismatch between unlimited wants and the limited resources that gives rise to three central problems faced by every economy.

Contents:
a. What to produce and in what quantities?
An economy faces the problems of what to produce because the resources available to an economy are scarce. As resoruces are scarce, an economy cannot produce all those goods and services the society needs. Therefore, society has to take the crucial decision of what goods and services to be produced in an economy.

For example, the resources of an economy can be used for the production of food, defense equipment or luxury goods. It can also be used for education, health or entertainment. A national society has to make a priority list of items to be produced and allocate the available resources accordingly.

Once the decision regarding what to produce is taken, the next problem is to decide in what quantities the goods and services are to be produced. It is important because the production of one good may lead to the withdrawal of the production of some other goods.

b. How to produce?
After taking the decision regarding the type and quantity of goods to be produced, the next question is ‘how to produce goods arid services’. This problem is related to the method or technology of production. Goods can be produced using different technologies.

There are mainly two technologies for producing goods, viz., labor-intensive technology and capital intensive technology. Labour intensive technology uses more labour compared to capital. On the other hand, capital intensive technology uses more caiptal compared to labour. The choice of technique depends upon various factors like the availability of labour force and capital resources and its prices.

c. For whom to produce?
The goods and services produced once should be distributed among the people of the economy. Whether it should be distributed equally among the people? Should the distribution of the goods be in such a way that at least minimum consumption level has to be attained by everyone in the economy? Should everyone get primary health and education?

Conclusion:
Thus it can be concluded that every economic system faces three basic problems. The solution to these economic problems depends upon the nature of the economic system.

Students can Download Chapter 14 Biomolecules Questions and Answers, Plus Two Chemistry Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus Two Chemistry Chapter Wise Questions and Answers Chapter 14 Biomolecules

Plus Two Chemistry Biomolecules One Mark Questions and Answers

Question 1.
Which of the following is an example of globular protein?
(a) Myosin
(b) Collagen
(c) Insulin
(d) Keratin
Answer:
(c) Insulin

Question 2.
The vitamin essential for blood clotting is
Answer:
Vitamin K

Question 3.
Which base is present in RNA but not in DNA?
(a) Uracil
(b) Thymine
(c) Guanine
(d) ytosine
Answer:
(a) Uracil

Question 4.
Say TRUE or FALSE:
The coagulation of egg white on boiling is an example of protein denaturation.
Answer:
True

Question 5.
The linkage that holds monosaccharide units together in a polysaccharide is called …………………….
Answer:
Glycosidic linkage

Question 6.
Proteins are essential for growth in animals. They are build up of amino acid molecules. How are different amino acid molecules linked in a proteins?
Answer:
By peptide linkage.

Question 7.
What are the different types of RNA found in the cell?
Answer:
m-RNA, t-RNA, r-RNA

Question 8.
Lactose is made of ………………….
Answer:
β -D galactose and β -D glucose

Question 9.
Glucose does not react with ………………..
a) Br₂/H₂O
b) NH₂OH
c) HI
d) NaHSO₃
e) CH₃-CO-O-CO-CH₃
Answer:
(d) NaHSO₃

Question 10.
Anaemia is caused by the deficiency of vitamin ………………………
Answer:
B₁₂

Question 11.
The number of chiral C atoms on glucose and fructose are
Answer:
4 in glucose and 3 in fructose

Question 12.
Glucose on oxidation with bromine water give …………………………
Answer:
Gluconic acid

Question 13.
Name the vitamin responsible for the coagulation of blood.
Answer:
Vitamin K.

Plus Two Chemistry Biomolecules Two Mark Questions and Answers

Question 1.
Explain the denaturation of protein.
Answer:
When a protein is treated with acid, alkali or heated or subjected to change in pH, the secondary and primary structure of protein gets ruptured. Denaturation does not change the primary structure of proteins.

Question 2.
Why cannot vitamin C be stored in our body?
Answer:
Vitamin ‘C’ is a water soluble vitamin and they are readily excreted in urine and cannot be stored in our body.

Question 3.
Classify the following into monosaccharides and disaccharides.
Ribose, 2-deoxyribose, maltose, galactose, fructose and lactose.
Answer:

• Monosaccharides – Ribose, 2-deoxyribose, galactose and fructose.
• Disaccharides – Maltose and lactose.

Question 4.
What do you understand by the term glycosidic linkage?
Answer:
The two monosaccharide units are linked together by an oxide or either linkage formed by the loss of water molecules. Such a linkage called glycosidic linkage.

Question 5.
Distinguish between essential and non-essential amino acids. Give examples.
Answer:

1. The amino acids which can be synthesized in our body are known as non-essential amino acids, eg. Glycine, Alanine.
2. Those amino acids which can not be synthesized in our body and must be obtained through diet are known as essential amino acids. eg. valine, Lysine.

Question 6.
What is ‘peptide linkage’ as related to proteins?
Answer:
The linkage, – CO – NH – which unites various amino acid units in a peptide molecule is called peptide linkage.

Question 7.
Amino acids show amphoteric behavior. Why?
Answer:
Amino acids contain both NH₂ & -COOH group and hence they exhibit amphoteric character.
NH₃⁺ – CH₂ – COO^–

Question 8.
What are reducing sugars? Give one example.
Answer:
Sugar units which are having free – CHO groups are reducing sugars, eg. Maltose.

Question 9.
What is primary structure of proteins?
Answer:
The primary structure gives an idea regarding the sequence in which amino acids are arranged.

Question 10.
Differentiate between fibrous & globular proteins.
Answer:
Fibrous proteins have threads lying side by side to form a fiber-like structure, e.g. Keratin. Globular proteins have molecules which are folded into compact units that often approach spherical shape.

Plus Two Chemistry Biomolecules Three Mark Questions and Answers

Question 1.
D-glucose is obtained in two different forms, α- D- glucose, and β-D-glucose.

1. In which name the α and β forms of glucose are known?
2. Explain the difference in their configuration with diagram.

Answer:

1. They are known as anomers.
2. Anomers are a pair of stereo isomeric ring forms of a sugar which differ in configuration only around first carbon atom.

Question 2.
Complete the following table:

Answer:

1. Reducing
2. Fructose
3. Disaccharide
4. Reducing
5. Disaccharide
6. Non-reducing

Question 3.
There are two types of nucleic acids, DNA and RNA.

1. Identify the sugar that is present in DNA and RNA.
2. Give the differences between DNA and RNA.

Answer:

1. Sugar that is present in DNA and RNA:

• DNA – β-D-2-deoxyribose
• RNA – β-D-ribose

2.

Question 4.
Classify the given vitamins as fat soluble and water soluble.

1. Vitamin A, D, B, E, K, C
2. Name a deficiency disease caused by the deficiency of Vitamin A.
3. The deficiency of which vitamin is responsible for the disease Rickets?

Answer:

1. Fat soluble – Vitamins A, D, E and K. Water soluble – Vitamins B and C
2. Night blindness
3. Vitamin D

Question 5.
Write the products obtained when glucose is treated with the following reagents?

• HF
• Bromine water
• HNO₃

Answer:

• When glucose is heated with HI, n-Hexane is formed.
• When glucose is treated with bromine water, it is oxidised to gluconic acid.
• Glucose is oxidised by HNO₃ to saccharic acid.

Question 6.
What is the basic structural difference between starch and cellulose?
Answer:
Starch has 2 components namely amylose and amylopectin. Amylose is a long unbranched chain made of α-D-(+)-glucose units held by C1 – C4 glycosidic linkage.

Amylopectin is a branched chain polymer of α-D-glucose units in which chain is formed by C1 – C4 glycosidic linkage whereas branching occurs by C1 – C6 glycosidic linkage. Cellulose is a straight chain polysaccharide composed of only β-D-glucose units joined by C1 – C4 glycosidic linkage.

Plus Two Chemistry Biomolecules Four Mark Questions and Answers

Question 1.
Amino substituted carboxylic acids are called amino acids.

1. Analyse the statement and explain what are essential amino acids?
2. How many essential amino acids are there?
3. Give two examples of essential amino acids.

Answer:

1. The amino acids which can be synthesized in our body are known as non-essential amino acids, eg. Glycine, Alanine
   Those amino acids which can not be synthesized in our body and must be obtained through diet are known as essential amino acids. eg. valine, Lysine
2. Ten
3. Valine and Lysine

Question 2.
Starch on enzymatic hydrolysis by diastase gives a reducing disaccharide ‘A’ which undergoes hydrolysis by enzyme maltase to form ‘B’ which is also a reducing sugar.

1. Identify the compound ‘A’ and ‘B’ with suitable chemical equations.
2. Explain the term reducing sugar.

Answer:
1. Compound A-Maltose
Compound B – Glucose

b) All those carbohydrates which contain free aldehydic or ketonic group to reduce Tollens reagent and Fehling’s solution and are called reducing sugars, e.g. Glucose, Fructose.

Question 3.
In the following table, the names of Vitamins, their sources, and deficiency diseases are tabulated in the wrong order. Match them in the correct order.

Answer:

Question 4.

1. Draw the pyranose structures of the α and β forms of glucose.
2. Draw the furanose structures of the α and β

Answer:
1.

2.

Question 5.
When egg is boiled its physical structure changes.

1. Is there any change in its chemical nature?
2. Mention the peculiar type of bond present in proteins.
3. When egg is boiled it become hard. Why? Explain.

Answer:

1. No
2. Peptide bond
3. This is due to denaturation of protein. On boiling egg, the soluble form of globular proteins undergo coagulation to give fibrous proteins which are insoluble in water.

Question 6.

1. What type of bonding helps in stabilising the α – helix structure of proteins?
2. What is nucleotide?

Answer:
1. Intermolecular hydrogen bonding between -NH group of each amino acid and carbonyl group of an adjacent turn of the helix.

2. The repeating structural units of nucleic acids are called nucleotides.

• Pentose sugar + Base → nucleoside
• Nucleoside + Phosphoric acid → nucleotide

Question 7.

1. What do you mean by isoelectric point of amino acids?
2. What are Zwitter ions? Give one example.

Answer:

1. The pH at which the Zwitter ions do not migrate neither towards cathode nor towards anode is known as isoelectric point of the amino acids.

2. Amino acids possess both acidic and basic group, they generally exist as dipolar ions called Zwitter ions.
e.g. glycine H₃N⁽⁺⁾ – CH₂ – COO^(-)

Plus Two Chemistry Biomolecules NCERT Questions and Answers

Question 1.
Classify the following into monosaccharides and disaccharides.
Ribose, 2-deoxyribose, maltose, galactose, fructose and lactose.
Answer:

1. Monosaccharides – Ribose, 2-deoxyribose, galactose and fructose.
2. Disaccharides – Maltose and lactose.

Question 2.
What do you understand by the term glycosidic linkage?
Answer:
In oligosaccharides and polysaccharides, the two monosaccharide units are linked together by an oxide or ether linkage formed by the loss of water molecules. Such a linkage between two monosaccharide units through oxygen atom is called glycosidic linkage.

Question 3.
What is the basic structural difference between starch and cellulose?
Answer:
Both starch and cellulose contain a large number of α -D(+)-glucose units. Starch consists of two components:

1. Amylose which is a linear polymer and
2. Amylopectin which is a branched polymer but in both the D-glucose units are linked through α -glycosidic linkage between C1 of one glucose with C4 of next glucose unit. In amylopectin branching occurs by C1-C6 glycosidic linkage.

Cellulose is only a linear polymer of D-glucose units joined through β -glycosidic linkage between C1 of one glucose with C4 of next glucose unit.

Question 4.
Enumerate the reactions of D-glucose which cannot obe explained by its open chain structure.
Answer:

1. Glucose does not give 2,4-DNP test, Schiff’s test and it does not form the hydrogen sulphite addition product with NaHSO₃.
2. The pentaacetate of glucose does not react with hydroxylamine.
3. Glucose exists in two different crystalline forms such as α – form and β -form.

Question 5.
What is the difference between a nucleoside and a nucleotide?
Answer:
Nucleoside is formd by condensation of a purine or pyrimidine base with pentose sugar at position 1. When nucloeside is linked to phosphoric acid at 5 position of sugar moeity, we get a nucleotide. So a nucleoside has two units: pentose sugar and a base while a nucleotide has three units: phosphate group, pentose sugar and a base.

Students can Download Chapter 15 Polymers Questions and Answers, Plus Two Chemistry Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus Two Chemistry Chapter Wise Questions and Answers Chapter 15 Polymers

Plus Two Chemistry Polymers One Mark Questions and Answers

Question 1.
Orion is a polymer of
(a) Styrene
(b) Tetrafluoroethylene
(c) Caprolactam
(d) Acrylonitrile
Answer:
(d) Acrylonitrile

Question 2.
Buna-S is a copolymer of styrene and ……………
Answer:
1,3-Butadiene

Question 3.
F₂C = CF₂ is a monomer of
(a) Glyptal
(b) Teflon
(c) Nylon 6
(d) PVC
Answer:
(b) Teflon

Question 4.
Say TRUE or FALSE :
Chloroprene is an addition polymer of Neoprene.
Answer:
False

Question 5.
Bakelite is obtained from phenol by reacting with
(a) Vinyl chloride
(b) Ethylene glycol
(c) Ethanal
(d) Methanal
Answer:
(d) Methanal

Question 6.
Which one of the following is an example of a biode-gradable polyester
(a) PHBV
(b) PET
(c) Nylon
(d) Bakelite
Answer:
(a) PHBV

Question 7.
Novalac is ……………
Answer:
Phenol – formaldehyde resin

Question 8.
Ziegler-Natta catalyst is used in the preparation of …………….
Answer:
HDP

Question 9.
Nylon is a ………………….
Answer:
Polyamide

Question 10.
The polymer used in the manufacture of lacquers is ……………….
Answer:
Glyptal

Plus Two Chemistry Polymers Two Mark Questions and Answers

Question 1.
PVC is commonly used to make pipes.

1. What is the monomer of PVC?
2. What is the purpose of PVC covering of electrical connecting wire?

Answer:

1. Vinyl chloride
2. To provide electrical insulation.

Question 2.
Name the monomer units of natural rubber.
Answer:
2-Methyl-1,3-butadiene or Isoprene

Question 3.
Name two commercially important synthetic polymers. Also name their monomers.
Answer:

1. Nylon 6,6 – Hexamethylene diamene and Adipic acid
2. Bakelite – Phenol and Formaldehyde

Question 4.
What are polymers? Based on structure, how they are classified?
Answer:
Polymers are compounds of higher molecular mass formed by the combination of large number of small molecules.
Based on structure polymers are classified into 3 types:

1. Linear polymers
2. Branched polymer
3. Cross linked or network polymers

Question 5.
How are the polymers classified on the basis of molecular forces?
Answer:
Based on molecular forces polymers are classified into four subgroups.

1. Elastomers
2. Fibres
3. Thermoplastic polymers
4. Thermosetting polymers

Question 6.
What are bio-degradable polymers?
Answer:
These are polymers which undergo degradation by the action of microorganisms, eg. Nylon 2-nylon 6

Question 7.
Name the monomers of Terylene and Buna-N?
Answer:
Ethylene glycol and terephthalic acid are the monomers of terylene. Buna-N is a copolymer of 1, 3-Butadiene and Vinyl cyanide.

Question 8.
Write the names of monomers of the following polymers.

1. Glyptal
2. Bakelite

Answer:

1. Glyptal → Ethylene glycol and Phthalic acid
2. Bakelite → Phenol and Formaldehyde

Question 9.
Explain the term copolymerisation and give two examples.
Answer:
Copolymerisation is a process in which a mixture of more than one monomeric species is allowed to polymerise. The copolymer contains multiple units of each monomer in the chain. The examples are copolymers of 1,3-butadiene and styrene (Buna-S) and 1, 3-butadiene and acrylonitrile (Buna-N).

Question 10.
How does the presence of double bonds in rubber molecules influence their structure and reactivity?
Answer:
In this polymer the double bonds are located between C₂ and C₃ of isoprene units. This cis-configuration about double bonds do not allow the chains to come closer for effective attraction due to weak intermolecular attractions. Hence, the natural rubber has a coiled structure and shows elasticity.

Question 11.
Write the monomers of Teflon and Neoprene.
Answer:

• Teflon – Tetrafluoroethene
• Neoprene – 2-Chloro-1,3-butadiene

Question 12.
What is PHBV? What is its importance in polymer chemistry?
Answer:
PHBV is polyhydroxy butyrate – co – β – hydroxy valerate. PHBV is a biodegradable polymer.

Question 13.
What is meant by vulcanisation?
Answer:
The process of heating natural rubber with sulphur to improve its properties is called vulcanisation.

Plus Two Chemistry Polymers Three Mark Questions and Answers

Question 1.

• What is bakelite?
• What is its use?
• Why bakelite is said to be an example for thermosetting polymer?

Answer:

• Bakelite is the condensation polymer of phenol and formaldehyde.
• It is used for the manufacture of electrical plugs and switches.
• Bakelite contains cross linked molecules which on heating undergo extensive cross linking in moulds and again become infusible. It cannot be reused. Hence, it is a thermosetting ploymer.

Question 2.
Classify the following compounds into natural and synthetic polymers.
(Starch, Nylon, Butadiene, Styrene rubber, Natural rubber, PVC, Cellulose)
Answer:
Natural polymers: Starch, Natural rubber, Cellulose Synthetic polymers: Nylon, Butadiene, Styrene rubber, PVC.

Question 3.
Write notes on

1. Linear polymer
2. Branched polymer
3. Cross linked polymer

Answer:

1. Here small monomer units are arranged one behind the other so as to form a chain.
2. Small monomer units combine together in such a way that branched arrangement is possible in the polymer.
3. A rigid arrangement is possible when different monomer units are connected by cross linking.

Question 4.
Some polymers are given below:

1. PVC
2. Teflon
3. Nylon 6,6.

Make a table using the above representing name of polymer, name of monomer and type of polymerisation.
Answer:

Question 5.
Distinguish between Buna-N and Buna-S.
Answer:
S Buna N: It is a synthetic rubber and it is a copolymer of 1,3-Butadiene and Vinyl cyanide.

is a synthetic polymer formed by the copolymerisation of 1,3-butadiene and styrene.

Question 6.
In a science exhibition, one student mixed two transparent liquids in a beaker and got a sticky material from the interface of two liquids and he claims that the material formed is nylon 6,6.

1. Name the two liquids he mixed.
2. Name the monomer of nylon 6.
3. Suggest two uses of nylon 6, 6.

Answer:
1. Hexamethylene diammine & adipic acid.
2. Caprolactum
3. Uses of nylon 6, 6:

• For making sheets, bristles for brushes.
• In textile industry.

Question 7.
Rubber is a polymer.

1. Name the monomer of natural rubber.
2. Discuss the importance of the vulcanisation of rubber.
3. How is Neoprene prepared?

Answer:

1. 2-Methyl-1, 3-butadiene (or Isoprene) is the monomer.

2. Vulcanised rubber has high elasticity, low water absorption, good resistance to oxidation and organic solvents.
3. Neoprene is formed by the free radical polymerisation of chloroprene.

Plus Two Chemistry Polymers Four Mark Questions and Answers

Question 1.
In rubber industry, natural rubber is processed using sulphur.

• What is the need of processing rubber in this way?
• Name this process.
• What is the monomer unit of natural rubber?

Answer:

• Natural rubber is a gummy substance which has poor elasticity when it is heated with sulphur, it becomes non sticky and more elastic.
• Vulcanisation
• 2-Methyl-1, 3-butadiene or Isoprene

Question 2.
Fill in the blanks:
Table

Answer:

1. Vinyl chloride
2. Glyptal
3. 1,3-butadiene and acrylonitrile
4. Neoprene

Question 3.

1. Give the monomeric repeating units of nylon 6 and nylon 6, 6.
2. Differentiate between addition polymerisation and condensation polymerization.

Answer:

1. monomeric repeating units:

1. Nylon – 6 – Caprolactam
2. Nylon – 66 – Adipic acid, Hexamethylene diamine

2. Difference between addition polymerisation and condensation polymerization:

• Addition polymer: Simple monomer units combine together to form polymer.
  Example: polythene.
• Condensation polymer: Simple monomer units combine together to form polymer followed by the removal of small molecules like H₂O, NH₃ etc.
  Example: Nylon-6,6,

Question 4.

1. What is polymerisation?
2. What is a homo-polymer?

Answer:

1. Polymerisation is the process of formation of polymers from respective monomers,
2. Homopolymers are polymers formed by the addition polymerisation of a single monomeric species.

Plus Two Chemistry Polymers NCERT Questions and Answers

Question 1.
What are natural and synthetic polymers? Give two examples of each type.
Answer:
Natural polymers are high molecular mass macromolecules and are found in plants and animals, e.g. proteins, nucleic acids.
Synthetic polymers are man-made high molecular mass macromolecules. These include synthetic- plastics, fibres and rubbers, e.g. polythene, dacron.

Question 2.
In which classes, the polymers are classified on the basis of molecular forces?
Answer:
On the basis of molecular forces present between the chains of various polymers, the classification of polymers is give as follows:

1. Elastomers
2. Fibres
3. Thermoplastics and
4. Thermosetting plastics

Question 3.
How do you explain the functionality of a monomer?
Answer:
Functionality of a monomer is the number of bonding sites in a monomer.

Question 4.
Is (NH-CHR-CO)_n, a homopolymer or copolymer?
Answer:
Since the unit (NH-CHR-CO)_n is obtained from a single monomer unit, it is a homopolymer.

Question 5.
How does the presence of double bonds in rubber molecules influence their structure and reactivity?
Answer:
From the structural point of view, the natural rubber is a linear cis-1, 4-polyisoprene. In this polymer, the double bonds are located between C₂ and C₃ of isoprene units. This cis-configuration about double bonds do not allow the chains to come closer for effective attraction due to weak intermolecular attractions. Hence, the natural rubber has a coiled structure and shows elasticity.

Students can Download Chapter 2 Electric Potential and Capacitance Questions and Answers, Plus Two Physics Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus Two Physics Chapter Wise Questions and Answers Chapter 2 Electric Potential and Capacitance

Plus Two Physics Electric Potential and Capacitance NCERT Text Book Questions and Answers

Question 1.
Two charges 5 × 10^-8C and -3 × 10^-8C are located 16 cm apart. At what point on the line joining the two charges is the electric potential zero?
Take the potential at infinity to be zero.
Answer:
Given q₁ = 5 × 10^-8C, r=16cm = 0.16m q₂= -3 × 10^-8C Let potential be zero at a distance × metre from positive charge q₁.
∴ r₁ = x meter
r₂ = (0.16 – x) metre
S0 V = \(\frac{1}{4 \pi \varepsilon_{0}}\left[\frac{q_{1}}{r_{1}}+\frac{q_{2}}{r_{2}}\right]\)

or 0.8 – 5x = 3x
or x = 0.1m = 10cm.

Question 2.
A regular hexagonal of side 10cm has a charge 5mC at each of its vertices. Calculate the potential at the centre of the hexagon.

Answer:
From the figure, we have
OP = OQ = OR = OS = OT = OU
= r = 10cm = 0.1m
And given q = 5µC = 5 × 10^-6C
∴ Potential at O due to all the charges

= 2.7 × 10⁶volt.

Question 3.
Two charges 2mC and -2mC are placed at points A and B 6cm apart.

1. Identify an equipotential surface of the system.
2. What is the direction of the electric field at every point on this surface?

Answer:

1. The plane normal to AB and passing through its mid-point has zero potential everywhere hence the plane is equipotential.
2. Normal to the plane is the direction AB.

Question 4.
A spherical conductor of radius 12cm has a charge of 1.6 × 10^-7C distributed uniformly on its surface. What is the electric field

1. Inside the sphere.
2. Just outside the sphere.
3. At point 18cm from the centre of the sphere?

Answer:
1. Zero

2.

3.

Question 5.
A parallel plate capacitor with air between the plates has a capacitance of 8pF (1 pF=10^-12F). What will be the capacitance if the distance between the plates is reduced by half, and the space between them is filled with a substance of dielectric constant s?
Answer:
The capacitance of capacitor with air as dielectric is given by
C = \(\frac{\varepsilon_{0} A}{d}\)
Given C = 8pF = 8 × 10^-12F …………(1)
If C₁ is new capacitance when d₁ = \(\frac{d}{2}\) and space is filled with a substance of dielectric constant k=6.
Then

Using Eq.(1)
C₁ = 12 × 8 × 10^-12F
or C₁ = 96pF.

Question 6.
Three capacitors each of capacitance 9pF are connected in series.

1. What is the total capacitance of the combination?
2. What is the potential difference across each capacitor, if the combination is connected to a 120 volt supply?

Answer:
Given C₁ = C₂ = C₃ = 9pF = 9 × 10^-12F; V= 120 volt.
1. Total capacitance of the series combination is given by

∴ C = 3 × 10^-12F = 3pF.

2. Let q be the charge on each capacitor. Then, sum of the potential difference across their plates must be equal to 120 V.
ie. V₁ + V₂ + V₁ = 120

or q = 360 × 10^-12C
Since, all the capacitors are of same capacitance,

Plus Two Physics Electric Potential and Capacitance One Mark Questions and Answers

Question 1.
A hollowing metallic sphere of radius 10cm is charged such that potential on its surface is 80V. the potential at the center of the sphere would be.
(a) 80 V
(b) 800 V
(c) zero
(d) 8 V
Answer:
(a) 80 V

Question 2.
When air is replaced by a dielectric medium of constant K, the maximum force of attraction between two charges separated by a distance.
(a) increases k times
(b) remains unchanged
(c) decreases k times
(d) increases k^-1 times
Answer:
(c) decreases k times
Explanation : F_m = \(\frac{\mathrm{F}_{0}}{\mathrm{K}}\) i.e., Decrease K times.

Question 3.
Charge q₂ is at the center of a circular path with radius r. work done in carrying charged q₁ once a round this equipotential path, would be.

Answer:
(c) zero

Question 4.
Pick out a vector quantity from the following
(i) Electric potential
(ii) Electric potential gradient
(iii) Electric potential energy
(iv) Electric flux
Answer:
(ii) Electric potential gradient

Question 5.
“The surface of a charged conductor is an equipotential surface”. Comment on this statement.
Answer:
In a charged conductor, at any point inside or at the surface, the potential is same. So the surface is equipotential.

Question 6.
Pick the odd one out of the following
(i) eV
(ii) Volt
(iii) Mega Volt
(iv) Millivolt
Answer:
(i) eV (eV is the unit of energy).

Plus Two Physics Electric Potential and Capacitance Two Mark Questions and Answers

Question 1
Figure shows a parallel plate air capacitor of plate area of 100cm² and separation 5mm. A potential difference of 300v is established between its plates by a battery.

1. Calculate the capacitance and charge on the capacitor.
2. After disconnecting the battery, the space between the plate Js filled by ebonite (k=2.6). Then calculate the capacitance and charge on capacitor.

Answer:
1.

= 17.6 pF
Q = CV= 17.6 × 10^-12 × 300 = 5.2 × 10^-9C

2. C = \(\frac{A K \varepsilon_{0}}{d}=\frac{K A \varepsilon_{0}}{d}\)
= 2.6 × 17.6 × 10^-12 = 45.76pF.

Question 2.
Fill in the blanks

1. 6.25 × 10¹⁸ electrons =………..C
2. 6.25 × 10¹⁸ eV =…………J

Answer:

1. 1 coulomb
2. 1 J

Question 3.
Potential is a scalar quantity. Potential gradient is a vector quantity Negative of potential gradient is another vector quantity. It is
1.

• electric force
• electric flux
• electric field intensity
• none

2. What is magnitude and direction of above quantity in the case of a point charge
Answer:

1. Electric field
2. Direction of electric field is outward for positive charge and inward for negative change

Question 4.

1. Dielectric strength of air is 3 × 10⁶ V/m. What does it mean?
2. High power lines cannot be insulated. Why?

Answer:

1. When electric field on air exceeds the 3 × 10⁶ v/m, air becomes conductor and conduct electricity.
2. Insulator shows conducting property at high voltage.

Question 5.

Write whether true or false

1. In a charged conductor charge reside inside and outside of the conductor
2. In a charged conductor net field is zero inside the conductor
3. Potential is Zero inside the conductor
4. The entire part of the conductor (including surface of the conductor) is at constant potential.

Answer:

1. False
2. True
3. False
4. True

Plus Two Physics Electric Potential and Capacitance Three Mark Questions and Answers

Question 1.
Match the following.

Answer:

1. Electric field – force per unit (+ve) charge -NC^-1
2. Electric potential – Work done per (+ve) charge – JC^-1
3. Capacitance – charge per unit potential difference -Farad.

Question 2.
The data given below shows the variation of potential with charge during charging of a condenser.

1. Draw a graph with charge along the Y-axis and potential along the X-axis. Estimate capacity of the condenser from the graph.
2. Estimate the energy stored in the condenser from the graph.

Answer:
1.

2. Area enclosed by the graph represents total energy = 1/2 QV = 1/2 × 5 × 10^-6 × 25
= 62.5 × 10^-6 J

Question 3.
Many of the applications of capacitors depend on their ability to store energy.
1. In a charged capacitor energy is stored in the

• positively charged plate
• negatively charged plate
• electric field between the plates
• none of these

2. Draw a graph showing the variation of charge stored in a capacitor with its potential. How will you calculate the energy stored in the capacitor using the above graph?
Answer:
1. Electric field between the plates

2.

Area under the straight line graph gives the energy stored in the capacitor.

Question 4.
A and B are two points in an electric field produced by q. To bring a unit +ve charge from a to A, 10 J work is needed. To bring the same charge from. A to B, 2J work is needed.
1. What is the p.d, between A and B?

2. What are the potential at A and B?

Answer:

1. 2v
2. potential at A, V_A = 10v potential at B, V_B = 12v.

Question 5.

1. 1 coulomb = 6.25 × 10¹⁸ electrons, 1 Joule =……..eV
2. What is meant by 1 eV
3. Which is bigger unit J or eV? Justify for your answer.

Answer:
1. lev=1.6 × 10^-19 J
∴ 1J = \(\frac{1}{1.6 \times 10^{-19}}\) ev 1 J = 6.25 × 10¹⁸ ev.

2. 1 ev is the energy acquired by an electron, when it is accelerated through a potential difference of one volt.

3. Joule is bigger unit, 1J = 6.25 × 10¹⁸ eV.

Question 6.

1. Name the physical quantity which has its unit joule, coulomb^-1. Is it a vector or a scalar?
2. Two plane sheets of charge densities +σ and -σ are kept in air as shown in figure. What are the electric field intensities at point A and B?

Answer:
1. Electric potetial. Scalar.

2. Electric field at A E_A = 0
Electric field atB E_B = \(\frac{\sigma}{\varepsilon_{0}}\).

Question 7.
You are given 3 capacitors of capacities 3 µf, 2 µf, 1 µf You have to make a capacitors of capacitance less than 1 µf.

1. How do you arrange the capacitors, show by a diagram?
2. Write an expression for effective capacitance of the above combination and verify the result.

Answer:
1. Connect in series

2.

Question 8.
The arrangement of a capacitor is given below. The plate A is charged and the plate B is earthed, ‘d’ is the distance between two plates.
1. Write any one use of this capacitor.

2. Obtain an expression for capacitance of this arrangement.

3. A capacitor is made of a flat plate of area A and second plate having a stair like structure as shown in figure. The width of each stair is d and 2d. Find the capacitance of this arrangement.

Answer:
1. To store electric charges

2. C = \(\frac{A \varepsilon_{0}}{d}\)

3. It is equivalent to two capacitors connected in parallel.
C = C₁ + C₂

Question 9.
The dotted line indicate the surface such that they lie equi-distance from the charge ‘q’.

1. What is the name of this surface?
2. Write the properties of the surface.
3. Give a mathematical proof to any one of the properties.

Answer:
1. Equipotential surface.

2. properties of the surface:

• Direction of electric field is perpendicular to the equi potential surface,
• No work is done to move a charge from one point to another along the equi potential surface.

3. Work done = Potential difference × charge
= 0 × Charge = 0.

Question 10.

1. What is meant by potential at a point?
2. Obtain an expression for potential at a point
3. A wire is bent in a circle of radius 10cm. It is given a charge of 250µC which spreads on it uniformly. What is the electric potential at the centre?

Answer:
1. Potential at a point is the work done required bring a unit charge from infinity to that point without acceleration.

2. Potential due To A point charge:

Let P be a point at a distance Y from a charge +q. Let A be a point at a distance ‘x’ from q, and E is directed along PA. Consider a positive charge at A. Then the electric field intensity at ‘A’ is given by
\(E=\frac{1}{4 \pi \varepsilon_{0}} \frac{q}{x^{2}}\)
If this unit charge is moved (opposite to E} through a distance dx, the work done dw = – Edx
[-ve sign indicates that dx is opposite to E ]
So the potential at ‘P’ is given by

V = \(\frac{+q 1}{4 \pi \varepsilon_{0} r}\) (since \(\frac{1}{\infty}\) = 0).

3.

= 2.25 × 10⁷ v.

Plus Two Physics Electric Potential and Capacitance Four Mark Questions and Answers

Question 1.

1. Write any one use of capacitor
2. Obtain an expression for capacitance of a parallel plate capacitor
3. The Capacity of a parallel plate capacitor becomes 10µF when air between the plates is replaced by a dielectric slab (k =2). What is the capacity of the capacitor with air in between the plates?

Answer:
1. one use of capacitor:

• Capacitor is used to store electric charges
• It is used to prevent dc current.

2. Expression for capacitance of a capacitor:
Potential difference between two plates V= Ed

Capacitance C of the parallel plate capacitor,

C = \(\frac{\mathrm{A} \varepsilon_{0}}{\mathrm{d}}\)

3. C = 10µF
When dielectric slab is placed, New capacitance
C¹ = KC
10 × 10^-6 = 2 × C, C=5 × 10^-6F.

Question 2.
A charge of +5µC is placed in free space. P and Q are two points at 3mm and 5mm respectively from 5µC.

1. The work done to bring a + IC charge from infinity to a point ‘P’ is called

• capacitance
• dielectric constant
• potential energy
• electric potential

2. Calculate the workdone in above process.

3. Calculate the workdone to move a +IC charge from ‘P’to ‘Q’.

Answer:
1. Electric potential.

2. Work done w = VQ

3. The potential energy at p,

PE₂ = 9V
Work done to move IC from P to Q, W = PE₂ – PE₁
= 9 – 15
w = -6 J

Question 3.

1. “Electric field lines are always parallel to Equipotential surfaces.” Correct the statement if there is any mistake.
2. Draw the equipotential for a single positive point charge.

Answer:
1. Electric field lines are always perpendicular to Equipotential surfaces.

2.

Question 4.
E is the electric field intensity at any point in a uniform electric field.

1. What is meant by uniform electric field?
2. Represent a uniform electric field using lines of force.
3. Calculate energy stored per unit volume of the space if E=2V/m.

Answer:
1. Region where magnitude and direction of electric field remain same.

2. lines of force are parallel and equidistant.

3. Energy density = \(\frac{1}{2}\) ε_o E² = 1/2 × 8.85 × 1012 × 22
= 17.7 J/m3.

Question 5.
In a charged capacitors energy is stored
1.

• in+ve plate
• In dielectric
• In electric field

2. Derive an expression for energy stored in a capacitor.

3. Draw a graph between energy and charge, in electric field

Answer:
1. In electric field

2. If we supply a charge ‘dq’ to the capacitor, then work done can be written as,
dw = Vdq
dw = \(\frac{q}{c}\) dq (since v = \(\frac{q}{c}\))
∴ Total work done to charge the capacitor (from ‘0’ to ‘Q’) is

3.

Plus Two Physics Electric Potential and Capacitance Five Mark Questions and Answers

Question 1.

1. Identify the device

• Moving coil Galvanometer
• Cyclotron
• Photovoltaic cell
• Van-de-Graft electrostatic generator

2. Explain the construction and working of the above device

3. What happens if the upper metal sphere is replaced by a cubical shaped metal? Explain.

Answer:
1. Vandegraff generator

2. Van de graff generator:
Van de Graff generator is used to produce very high voltage.
Principle:
If two charged concentric hollow spheres are brought in to contact, charge will always flow from inner sphere to the outer sphere.
Construction and working:

The vande Graff generator consists of a large spherical metal shell, placed on an insulating stand. Let p₁ and p₂ be two pulleys. Pulley p₁ is at the center of the spherical shell S. A belt is wound around two pulleys p₁ and p₂.

This belt is rotated by a motor. Positive charges are sprayed by belt. Brush B₂transfer these charges to the spherical shell. This process is continued. Hence a very high voltage is produced on the sphere.

3. The charge density on the pointed edge is higher than flat surface. Hence charge will leak from the cubical shaped metal.

Question 2.
The figure below shows a non polar dielectric slab placed in between the plates of an uncharged parallel plate capacitor.
Area of each plate = A, Distance, of separation be¬tween the plates = d

1. If the dielectric slab is absent and the capacitor is charged to a surface charge density a, the electric field in between the plates is

• E = σε_o
• E = \(\frac{\sigma^{2}}{\varepsilon_{0}}\)
• E = \(\frac{\sigma}{\varepsilon_{0}}\)
• E = σε_o²

2. Redraw the given figure, which shows the align-ment of the nonpolar molecules, when the capacitor is charged.

3. Derive an expression for capacitance of the above capacitor with the dielectric slab in between the plates.
Answer:
1. E = \(\frac{\sigma}{\varepsilon_{0}}\)

2.

3. Effect of dielectric on capacitance:

Consider a capacitor of area A and charge densities +σ and -σ. Let d be the distance between the plates. If a dielectric slab is placed inside this capacitor, it undergoes polarization.

Let +σ_p and -σ_p be polarized charge densities due to polarization. Due to polarization electric field in between the plate becomes
E = \(\frac{\sigma}{\mathrm{K} \varepsilon_{0}}\) …….(1)
The potential difference between the plates,
V = Ed ………..(2)
Sub (1) in (2)
V = \(\frac{\sigma}{\mathrm{K} \varepsilon_{0}}\) d
Then the capacitance of capacitor

C = \(\frac{A \varepsilon_{0} K}{d}\)
The product ε₀K is the permittivity of the medium.

Question 3.
Three capacitors C₁, C₂ and C₃ are connected to a cell of emf V as shown in the figure.

1. The arrangement of these three capacitors are called………….

• parallel combination
• series combination
• LCR combination
• c-c combination

2. Find the effective capacitance of the above combination.

3.

The above graph shows the variation of potential in going from a to g. From the graph the relation among C₁, C₂ and C₃ is

• C₁ = C₂ = C₃
• 2C₁ = 2C₂ = C₃
• C₁ = C₂ = 2C₃
• C₁ = C₂ = C₃

Answer:
1. Series connection.

2. Capacitors in series:
Let three capacitors C₁,C₂ and C₃ be connected in series to p.d of V. Let V₁, V₂ and V₃ be the voltage across C₁, C₂ and C₃.

The applied voltage can be written as,
V=V₁ + V₂ + V₃ ………..(1)
Charge ‘q’ is same as in all the capacitor. So,

Substituting these values in (1),

If these capacitors are replaced by a equivalent capacitance ‘C’, then
V = \(\frac{q}{C}\)
Hence eq(2) can be written as
\(\frac{q}{C}=\frac{q}{C_{1}}+\frac{q}{C_{2}}+\frac{q}{C_{3}}\)
\(\frac{1}{C}=\frac{1}{C_{1}}+\frac{1}{C_{2}}+\frac{1}{C_{3}}\)
Effective capacitance is decreased by series combination.

3. From the graph, we get v₁ = 1 v, v₂ = 1 v, v₃ = 2v.
This arrangement is series. Hence charge stored in each capacitor is same.

C₁: C₂: C₃
1: 1: 1/2
2: 2: 1
2C₁: 2C₂: C₃

Question 4.
Two metal plates X and Y of the area ‘A’ are separated by a distance ‘d’, charged + and – respectively.

1. This arrangement is called………….
2. The arrangement store energy in the………..(Magnetic field, Electric field, Electromagnetic field, Gravitational field)
3. Derive an expression for the energy stored in the arrangement.
4. When we increase separation between two plates by keeping V constant, what happens to total energy stored in the system.

Answer:
1. Capacitor.

2. Electric field

3. If we supply a charge ‘dq’ to the capacitor, then work done can be written as,
dw = Vdq
dw = \(\frac{q}{c}\) dq (since v = \(\frac{q}{c}\))
∴ Total work done to charge the capacitor (from ‘0’ to ‘Q’) is

4. When we increase the separation between two plates, capacitance (c) decreases. The energy in the capacitor U = 1/2 CV² When c decreases, the energy decreases (because V is constant).

Question 5.
A combination of two conducting bodies separated by insulator can store electric charge
1. The above device is called………….

2. Derive on expression for capacitance of the device with air as medium.

3. If mica of dielectric constant Ks placed between the plates. What are its advantages? Explain action of mica in the case.
Answer:
1. capacitor.

2. Potential difference between two plates V= Ed

Capacitance C of the parallel plate capacitor,

3.

• When mica sheet is introduced, capacitance of capacitor increases
• Mica sheet will prevent electric breakdown.

Question 6.
When a charged particle moves in an electric field, work is done on the particle.
1. Pick out a vector quantity from the following

• electric potential
• electric potential gradient
• electric potential energy
• electric flux (1)

2. 5 J of work is done in moving a positive charge of 0.5C between two points. What is the potential difference between the points?

• 2.5V
• 10V
• 0.1V
• 5.5V (1)

3. Three-point electric charges q₁ = 6µC, q₂ = 4µC and q₃ = -8µC are placed on the circumference of a circle of radius 1 m as shown in the figure. What is the value of the charge q₄ placed on the circle if the potential at the centre of the circle is zero? (3)
Answer:
1. Electric potential gradient

2. 10V

3. Radius of the circle r = 1m
By the given condition
\(\frac{1}{4 \pi \varepsilon_{0}} \times \frac{1}{r}\) (q₁ + q₂ + q₃ + q₄) = 0
(q₁ + q₂ + q₃ + q₄) = 0
(6 + 4 – 8 + q₄) µC = 0
(2 + q₄) µC = 0
q₄ = -2µC.

Question 7.
Equipotential surface is a surface on which the electrical potential is the same at every point.
1. “Electric field lines are always parallel to Equipotential surfaces.” Correct the statement if there is any mistake. (1)

2. Draw the equipotential for a single positive point charge. (2)

3. A point charge +q is placed at the centre of a sphere of radius R. Another point charge +q is taken from a point A to another diametrically opposite point B on the surface of the sphere. Calculate the work done for this. (2)
Answer:
1. Electric field lines are always perpendicular to Equipotential surfaces.

2. Surface of the sphere is Equipotential in nature. So the potential difference between any points is zero. Since work done is the product of charge moving and the potential difference between the points, work done is equal to zero.

Question 8.
Capacitance of a capacitor depends on the size and shape of the conductors and on the dielectric material between them.
1. Draw the symbol of a variable capacitor. (1)

2. The plates of a parallel plate capacitor are connected to an ideal voltmeter. What will happen to the reading of the voltmeter if the plates of the capacitor are brought closer to each other in an insulating medium? (2)

3. The plates of a parellel plate capacitor in vacuum are 5mm apart and 1.5m² in area. A potential difference of 10kV is applied across the capacitor. Calculate
a. The capacitance
b. The charge on each plate.
c. magnitude of the intensity of electric field between the paltes.

Answer:
1.

2. Capacitance C = \(\frac{\varepsilon_{0} A}{d}\)
Potential difference V = \(\frac{q}{c}=\frac{q d}{\varepsilon_{0} A}\)
In an insulating medium charge remains the same,voltage is directly proportional to plate separation. Therefore, voltmeter reading decreases.

3.
a.

b. Q = CV = 2.66 × 10^-9 × 10 × 10³ = 2.66 × 10^-5 C.
c.

Question 9.
Capacitors can be combined to obtain any desired capacitance in an application.
1. You are given two capacitors of capacitance 20µF each. Draw a diagram to show how you will connect these capacitors to get 40µF capacitance. (1)

2. Two capacitors C₁ and C₂ are connected in series.
a. Draw a diagram of the above combination. (1)
b. If C₁ = 4µF, C₂ = 6µF and C₃ = 2.4µF and a potential difference of 100V is applied across the combination. Calculate the change stored in each capacitor.

Answer:
1.

2. Two capacitors C₁ and C₂ are connected in series:
a.

b. Effective capacitance C₁ anc C₂
C₁₂ = \(\frac{C_{1} C_{2}}{C_{1}+C_{2}}=\frac{4 \times 6}{4+6}\) = 2.4µF
Potential difference across C₁₂ = 100V
Charge stored on C₁₂, q₁₂ = C₁₂ × 100
q₁₂ = 2.4 × 10^-6 × 100
q₁₂ = 2.4 × 10^-4 C
Charge on C₁
q₁ = 2.4 × 10^-4C
Charge on C₂
q₂ = 2.4 × 10 ^-4C
Potential difference across C₃ = 100V
Charge on C₃
q₃ = C₃ × 100
q₃ = 2.4 × 10^-6 × 100
q₃ = 2.4 × 10^-4C.

Question 10.
Many of the applications of capacitors depend on their ability to store energy.
1. In a charged capacitor energy is stored in the

• positively charged plate
• negatively charged plate
• electric field between the plates
• none of these (1)

2. Draw a graph showing the variation of charge stored in a capacitor with its potential. How will you calculate the energy stored in the capacitor using the above graph?

3. An electric flash lamp has 20 capacitors each of capacitance 5µF connected in parallel. The lamp is operated at 100V. If the energy stored in the combination is completely radiated out in a single flash, how much energy will be radiated in a flash? (2)

Answer:
1. Electric field between the plates

2.

Area under the straight line graph gives the energy stored in the capacitor.

3. Effective capacitance C = 20 × 5µF = 100µF, V=100v,
Energy stored E = \(\frac{1}{2}\) CV
E = \(\frac{1}{2}\) × 100 × 10^-6 × 100² = 0.5 J

Students can Download Chapter 16 Chemistry in Everyday Life Questions and Answers, Plus Two Chemistry Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus Two Chemistry Chapter Wise Questions and Answers Chapter 16 Chemistry in Everyday Life

Plus Two Chemistry in Everyday Life One Mark Questions and Answers

Question 1.
Which of the following is a hypnotic drug?
(a) Luminal
(b) Salol
(c) Catechol
(d) Ranitidine
Answer:
(a) Luminal

Question 2.
Alitame is an example of ……………………….
Answer:
Artificial sweetner

Question 3.
Say TRUE or FALSE: Non-ionic detergents are used for dishwashing purpose.
Answer:
True

Question 4.
Which of the following is a bacteriostatic antibiotic?
(a) Pencillin
(b) Aminoglycosides
(c) Chloramphenicol
(d) Ofloxacin
Answer:
(c) Chloramphenicol

Question 5.
Antipyretics are medicinal compounds which
(a) lower body temperature
(b) relieve pain
(c) control hypertension
(d) remove acidity
Answer:
(a) lower body temperature

Question 6.
Name the macromolecules that are chosen as drug targets.
Answer:
Proteins, carbohydrates, lipids and nucleic acids.

Question 7.
Which of the following s not used as a neurologicaly active drug?
(a) Veronal
(b) Bithional
(c) Equanil
(d) Nardil
Answer:
(b) Bithional

Question 8.
Bithional is added to soap as an additive which per¬form as
(a) Herdenel
(b) Softness
(c) perfume
(d) Antiseptic
Answer:
(d) Antiseptic

Question 9.
Chemicaly Aspirin is …………….
Answer:
Acetyl Salicylic acid

Question 10.
Chemical compound used for the treatment stress are called ……………..
Answer:
tranquilizer

Question 11.
Terfenadine is commonly used as ……………
Answer:
Antibiotic

Plus Two Chemistry in Everyday Life Two Mark Questions and Answers

Question 1.
Explain the term ‘target molecules’ or ‘drug-targets’ as used in medicinal chemistry.
Answer:
Target molecules or drug-targets are the macromolecules such as carbohydrates, proteins, lipids, noucleic acids with which the drug interacts in our body to produce therapeutic effect.

Question 2.
What you mean by the term broad spectrum antibiotics? Explain.
Answer:
Antibiotics which are effective against several different types of harmful micro-organisms and thus capable of curing several infections are called broad spectrum antibiotics, e.g. Chloramphenicol.

Question 3.
Describe the following with suitable examples.

1. Tranquilizers
2. Antihistamines

Answer:

1. They are used for the treatment of stress or mental diseases. e.g. Barbituric acid
2. These are anti-allergic drugs and are used to treat allergy. e.g. skin rashes, conjunctivitis, nasal discharge, etc. e.g. brompheniramine, terfenadine

Question 4.
Bithional is added to soap. Give reason.
Answer:
It eliminates undesirable odour resulting from bacterial decompostion of organic matter on skin.

Question 5.
How do antiseptic and disinfectant differ? Explain with example.
Answer:
Both antiseptics and disinfectants are chemicals which either kill or prevent the growth of micro organisms. Antiseptics can be applied to living tissues. But disinfectants are applied to inanimate objects. They are harmful to living tissues, eg. Antiseptic – Dettol, Disinfectant – Phenol

Question 6.

1. What are artificial sweetening agents?
2. Name any two artificial sweetners.

Answer:

1. Substances which are used as sweetening agents in place of sugar but have no nutritive value are called artificial sweetening agents,
2. Sacharine and Aspartame are artificial sweetners.

Question 7.
What problem arises in using alitame as artificial sweetener?
Answer:
Alitame is a high potency sweetener. It is about 2000 times sweeter than sucrose. Therefore, the control of sweetness of food is difficult while using it.

Question 8.
Classify the following drugs into antihistamines transquilizers, analgesics and antibiotics.
Barbituric acid, Ranitidine, Morphine, Amoxycillin
Answer:

• Antihistamines – Rantidine
• Tranquilisers – Barbituric acid
• Analgesics – Morphine
• Antibiotics – Amoxycillin

Question 9.
What do you mean by bacteriocidal and bactereostatic antibiotics? Give example.
Answer:
Bacteriocidal antibiotics kills bacteria, e.g. pencillin Bacteriostatic antibiotics has inhibitory effects on bacteria, e.g. Tetracycline.

Question 10.
Why should not medicines be taken without consulting doctors?
Answer:
Only a doctor can diagnose the disease properly and prescribe the correct medicine in appropriate dose.

Question 11.
Which forces are involved in holding the drugs to the active site of enzymes?
Answer:
Forces such as ionic bonding, hydrogen bonding, van der Waals interaction or dipole-diple interaction.

Plus Two Chemistry in Everyday Life Three Mark Questions and Answers

Question. 1
Match the following:

Answer:

Question 2.

1. Give an example of tranquilizers.
2. Aspirin belongs to which type of analgesic?
3. Give an example for narcotic analgesic.

Answer:

1. Barbituric acid and its derivatives.
2. Non-narcotic/Non-addictive analgesics
3. Morphine

Question 3.
Match the following:

Answer:

Question 4.
Chemistry plays a major role in our daily life.

1. How are synthetic detergents better than soaps?
2. Give one example each for cationic and anionic detergents.

Answer:

1. Detergents can be used even in hard water and also in acidic medium.
2. Cationic detergent – Cetyl trimethyl ammonium bromide
   Anionic detergent – Sodium lauryl sulphate

Question 5.
Match A and B:

Answer:

Question 6.
While antacids and antiallergic drugs interfere with the function of histamines, why do these not interfere with the function of each other?
Answer:
Antacids and antiallergic drugs do not interfere with the function of each other because they work on different receptors. Thus, antihistamines (antiallergic drugs) do not affect the secretion of acid in stomach because they do not interact with the receptors present in the stomach wall.

Question 7.
A low level of noradrenaline is the cause of depression. What type of drugs are needed to cure this problem? Name two drugs.
Answer:
Drugs which can inhibit the enzymes which catalyse the degradation of noradrenaline are needed. This will slow down the process of metabolism of noradrenaline and will thus help in counteracting the effect of depression. Iproniazid and phenelzine are two such drugs.

Plus Two Chemistry in Everyday Life Four Mark Questions and Answers

Question 1.

1. What are the main constituents of dettol?
2. What is tincture of iodine? What is its use?
3. Name the substance which can be used as an antiseptic as well as disinfectant.

Answer:

1. Chloroxylenol and terpineol.
2. A 2-3% solution of iodine in alcohol-water mixture is called tincture of iodine. It is used as an antiseptic.
3. Phenol can be used as an antiseptic as well as a disinfectant. 0.2% solution of phenol is used as an antiseptic and 1% solution of phenol is used as disinfectant.

Question 2.

1. Differentiate between antagonists and agonists.
2. What are broad spectrum antibiotics?

Answer:
1. Drugs that bind to receptor site and inhibit its natural function are called antagonists. They are usefull when blocking of message is required. Drugs that mimic natural messenger by switching on the receptor are called agonists. They are useful when there is lack of natural chemical messenger.

2. They can kill or inhibit a wide range of bacteria.

Plus Two Chemistry in Everyday Life NCERT Questions and Answers

Question 1.
Name the macromolecules that are chosen as drug targets.
Answer:
Proteins, carbohydrates, lipids and nucleic acids.

Question 2.
Why should not medicines be taken without consulting doctors?
Answer:
Medicines should always be taken after consulting a doctor because any medicine if taken in overdose may act as a poison. Moreover, only a doctor can diagnose the disease properly and prescribe the correct medicine in appropriate dose.

Question 3.
Which forces are involved in holding the drugs to the active site of enzymes?
Answer:
Drug is held to the amino acid residues of the protein present on the active site of the enzyme through forces such as ionic bonding, hydrogen bonding, van der Waals’ interaction ordipole-diple interaction.

Question 4.
While antacids and antiallergic drugs interfere with the function of histamines, why do these not interfere with the function of each other?
Answer:
Antacids and antiallergic drugs do not interfere with the function of each other because they work on different receptors. Thus, antihistamines (antiallergic drugs) do not affect the secretion of acid in stomach because they do not interact with the receptors present in the stomach wall.

Question 5.
A low level of noradrenaline is the cause of depression. What type of drugs are needed to cure this problem? Name two drugs.
Answer:
Drugs which can inhibit the enzymes which catalyse the degradation of noradrenaline are needed. This will slow down the process of metabolism of noradrenaline and will thus help in counteracting the effect of depression. Iproniazid and phenelzine are two such drugs.

Students can Download Chapter 7 Directing Questions and Answers, Plus Two Business Studies Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus Two Business Studies Chapter Wise Questions and Answers Chapter 7 Directing

Plus Two Business Studies Directing One Mark Questions and Answers

Question 1.
“It is an important managerial function that initiates action” What this managerial function is called?
Answer:
Directing

Question 2.
Supervision is an element of ………………………….
(a) Staffing
(b) Directing
(c) Organizing
Answer:
(b) Directing

Question 3.
Overseeing the subordinates at work is called …………
Answer:
Supervision

Question 4.
Which among the following is an example of upward communication?
(a) Circular
(b) Complaints
(c) Memos
(d) Notices
Answer:
(b) Complaints

Question 5.
Which one of the following is not an element of direction?
(a) Motivation
(b) Communication
(c) Delegation
(d) Supervision
Answer:
(c) Delegation

Question 6.
Arrange the following elements in the correct sequence.
Receiver → Sender → Message → Decoding → Feedback → Encoding → Channel
Answer:
Sender → Message → Channel →Encoding → Receiver → Decoding → Feedback

Question 7.
The network of informal communication is called ………………
Answer:
Grapevine communication

Question 8.
Grapevine is
(a) Formal communication
(b) Barrier to communication
(c) Lateral communication
(d) Informal communication
Answer:
(d) Informal communication

Question 9.
Status comes under the following type of barriers.
(a) Semantic barrier
(b) Organisational barrier
(c) Non Semantic barrier
(d) Psychological barrier
Answer:
(b) Organisational barrier

Question 10.
Ability of a leader to look at things from others point of view is called ……………
Answer:
Empathy

Question 11.
The production manager and the marketing manager in KEL communicates directly. Identify the type of communication.
Answer:
Horizontal communication

Question 12.
“Translation of ideas into meaningful language by the sender” Identify this concept.
Answer:
Encoding

Question 13.
The process of converting the message into communication symbols is known as ……………….
Answer:
Encoding

Question 14.
The communication network in which all subordinates under a supervisor communicate through supervisor only is:
(a) Single chain
(b) Y pattern
(c) Wheel
(d) Freeflow
Answer:
(c) Wheel

Question 15.
People interpret the same message in different ways depending upon their attitude, experience, education… etc. This is an example of ……………..
(a) Status barrier
(b) Semantic barrier
(c) Channel barrier
(d) Organizational barrier
Answer:
(b) Semantic barrier

Question 16.
Horizontal and Diagonal communication reduces ………………. barrier in communication.
(a) Semantic Barrier
(b) Status Barrier
(c) Organization Barrier
(d) Overload Barrier
Answer:
(c) Organization Barrier

Question 17.
Which among the following is an example of downward communication?
a) Suggestions
b) Complaints
c) Requests
d) Orders
Answer:
(d) Orders

Question 18.
“Persons of lower status do not feel free to talk to superiors”. Identify the Communication Barrier.
(a) Semantic Barrier
(b) Status Barrier
(c) In attention Barrier
(d) Barrier in Superior
Answer:
(b) Status Barrier

Question 19.
The communication network in which all subordinates under a manager communicate through the manager only is:
(a) Wheel Pattern
(b) Chain Pattern
(c) Circular
(d) Free flow
Answer:
(a) Wheel Pattern

Question 20.
The highest level need in the need Hierarchy of Abraham Maslow:
(a) Safety needs
(b) Belongingness needs
(c) Self actualisation needs
(d) Prestige needs
Answer:
(c) Self actualisation needs

Question 21.
Two messages are given below.

1.  “You must complete the work before 2 pm tommorrow”, the Factory Manager said to the Factory Supervisor.
2.  “Increase the sales as there is huge stock in hand”, the production Manager said to the Marketing Manager.

Identify the flow of communication in the above situations.

Answer:

1. Downward communication
2. Horizontal communication

Question 22.
Correct the following diagram.

Answer:
Sender → Message → Encoding → Channel → Receiver → Decoding → Feedback

Question 23.

Identify the communication network.
Answer:
Wheel Pattern

Question 24.
Observe the following diagram.

1. Identify the type of communication depicted in the diagram.
2. If all the persons can communicate with one another, what should the pattern be called?

Answer:

1. Circle pattern
2. Free flow

Question 25.
Sometimes emotions or state of mind stand in way of effective communication. Name the type of barriers cited above.
Answer:
Psychological barriers

Question 26.
Sometimes subordinates may feel reluctant to transit correct information to the superiors. The subordinate most often held back the unpleasant facts or may not report the true facts.

1. Identify the type of communication barrier referred to this context.

Answer:
1. Status barrier

Question 27.
There are some basic needs of an individual like need for food, clothing and shelter in the Maslow’s Need Hierarchy Theory. These needs are called:
(a) Esteem needs
(b) Social needs
(c) Physiological needs
(d) Safety needs
Answer:
(c) Physiological needs

Question 28.
The motivation theory which classifies needs in hierarchical order is developed by …………………
a) Fred Luthans
b) Scott
c) Abraham Maslow
d) Peter F. Drucker
Answer:
(c) Abraham Maslow

Question 29.
Arrange the following human desires in the hierarchy as suggested by Abraham Maslow.

1. Pension for old age
2. Feeling of self-confidence
3. Need to belong to a group
4. Need for food
5. Need for realization of goals in life

Answer:

1. Safety need
2. Esteem need
3. Social need
4. Physiological need
5. Self actualisation need

Question 30.
Arrange the following desires of a human being in the hierarchy as suggested by Abraham H Maslow.

1. Friendship
2. Life ambitious
3. Status
4. Food
5. Job security

Answer:

Question 31.
Distinguish between financial & non-financial incentives.

1. Commission
2. Bonus
3. Perquisites
4. Promotion
5. Recognition
6. Sharing of profit
7. Participation in decision making
8. Retirement benefits

Answer:

Question 32.
Take his own decisions and compel others to follow it. Which type of leadership style is mentioned here?
Answer:
Autocratic style

Question 33.
Give freedom to the subordinates to take part in decision making process is …………………
Answer:
Laissez-faire style

Question 34.
A communication network which allows a subordinate to communicate with his immediate superior and superior of his immediate superior is called ………………..
(a) Free flow
(b) Inverted V
(c) Circle
(d) Wheel
Answer:
(b) Inverted V

Question 35.
Distinguish the following channels as formal & informal.

1. Gossip network
2. Circle network
3. Probability network
4. Wheel network
5. Free flow
6. Single strand network
7. Cluster network

Answer:

Plus Two Business Studies Directing Two Mark Questions and Answers

Question 1.
Draw a diagram showing the elements of direction.
Answer:

Question 2.
What is directing?
Answer:
Directing refers to the process of instructing, guiding, counselling, motivating and leading people in the organisation to achieve its objectives.

Question 3.
Enumerate any two features of directing.
Answer:
Features

1. Directing initiate action
2. Directing takes place at every level of management
3. Directing is a continuous process
4. Directing flows from top to bottom

Question 4.
Explain the term Motivation.
Answer:
Motivation:
Motivation is the process of stimulating people to action to accomplish desired goals. Motivation depends upon satisfying needs of people.

Question 5.
In Maslow’s need hierarchy identify the needs which can be satisfied with financial incentives and also those which can be satisfied with non-financial incentives?
Answer:
Needs which can be satisfied with financial incentives are physiological needs, safety needs and social needs. Needs satisfied by non-financial incentives are esteem needs and self actualization needs.

Question 6.
What is incentive?
Answer:
An incentive is something which induces an individual to respond in a desired manner.

Question 7.
Define leadership.
Answer:
Leadership:
Leadership can be defined as the process of influencing the behaviour of employees at work towards the accomplishment of organisational objectives.

Plus Two Business Studies Directing Three Mark Questions and Answers

Question 1.
The diagram of communication network system adopted by Sahara Ltd is as follows.
Answer:
1)

2)

3)

Question 2.
“Informal communication is also known as grapevine communication”. Explain.
Answer:
Informal Communication:
Communication that takes place without following the formal lines of communication is said to be informal communication. It results from the social interaction among the members.

It satisfies the social needs of members in the organisation. The network of informal communication is known as Grapevine. It is so called because the origin and direction of flow of communication cannot be easily traced out.

Plus Two Business Studies Directing Four Mark Questions and Answers

Question 1.
“Managerial functions cannot be carried out without an efficient system of communication.”

1. Do you agree?
2. Give any three reasons in support of your answer.

Answer:
1. Yes. Communication is one of the most important function of management.
2. Importance of Communication:

• Acts as basis of co-ordination: Communication acts as the basis of co-ordination.
• Helps in smooth working of an enterprise: It is only communication, which makes smooth working of an enterprise possible.
• Acts as basis of decision making: Comm Plication provides needed information for decision making.
• Increases managerial efficiency: Communication lubricates the entire organisation and keeps the organisation at work with efficiency.

Question 2.
Give the communication process.
Answer:
Grapevine communication

Question 3.

1. What is grapevine communication?
2. How is both useful and a cause for disturbance in an organization?

Answer:
1. grapevine communication:
The network or pathway of Informal communication is known as grapevine communication. Because the origin and direction of flow of the informal mes-sages cannot be easily traced.

2. useful and a cause for disturbance in an organization:
a. Advantages of Informal Communication:

1. Employees can develop friendly relationship.
2. It is very flexible and faster than formal communication.
3. Employees attitudes, reactions, etc. to the plans and policies can be easily ascertained.
4. It reduces tension in employer-employee relations.
5. It can be used in conveying certain information which cannot be passed through official channel.
6. Special efforts and expenses are not necessary for informal communication.

b. Disadvantages of Informal Communication:

1. It tends to carry inaccurate information.
2. Its origin cannot be traced and responsibility cannot be fixed.
3. It is unsystematic and cannot be relied upon.
4. It leads to leakage of confidential information.
5. It often carries rumours and misunderstanding.

Plus Two Business Studies Directing Five Mark Questions and Answers

Question 1.
Explain the ‘communication network’.
Answer:
Communication network:
It refers to the pattern through which members of work groups communicate.
The pattern through which communication flows within the organisation is generally indicated through communication network. Some of the communication networks are:

1. Single Chain:
This network exists between a supervisor and his subordinates. Here communication flows from every superior to his subordinate through single chain.

2. Wheel:
In wheel network, all subordinates under one superior communicate through him only. The subordinates are not allowed to communicate among themselves.

3. Circular:
In circular network, the communication moves in a circle. Each person can communicate with his adjoining two persons.

4. Free flow:
In this network, each person can communicate with others freely.

5. Inverted V:
In this network, a subordinate is allowed to communicate with his immediate superior as well as his superior’s superior.

Question 2.
Match the following:

Answer:

Question 3.
Discuss the steps involved in the process of communication.
Answer:
Elements of Communication Process

1. Sender: The sender is the person who sends message or idea to the receiver.
2. Message: Message is the subject matter of communication.
3. Encoding: It is converting the message into communication symbols such as words, pictures, etc.
4. Media: It is the path through which encoded message is transmitted to receiver.
5. Decoding: It is the process of converting encoded symbols of the sender.
6. Receiver: Receiver is the person who receives the message.
7. Feedback: It includes all those actions of receiver indicating that he has received and understood message of sender.
8. Noise: Noise means some obstruction or hindrance to communication.

Question 4.
Re-arrange the following needs in the order of Abraham Maslow’s Need Hierarchy Theory of Human Needs.

Answer:

Question 5.
Mr.Valsalan, a manager of Shatu Ltd, traces out the needs of the employees in the organization which are as follows.

• Security in old age, state of illness.
• Dignity, self respect
• Protection against fire and accidents
• Better clothing and shelter
• Economic security
• Self-fulfilment
• Love and affection, friendship

Arrange the needs under the framework of Abraham Maslow’s theory. Prepare a chart based on it.
Answer:

Question 6.

1. The function of a lower level manager by which he oversee the working of employees and control their activities is called …………………
2. What is its need?

Answer:

1. Supervision

2. Importance of supervision:

• A good supervisor acts as a guide, friend and philosopher to the workers.,
• Supervisor acts as a link between workers and management. It helps to avoid misunderstandings and conflicts among the management and workers.
• Supervisor provides good On the Job training to the workers and employees.
• A supervisor with good leadership qualities can build up high morale among workers.
• A good supervisor analyses the work performed and gives feedback to the workers.
• Supervisors help to maintains harmony among workers.

Question 7.
Explain Maslow’s Need Hierarchy Theory of Motivation.
Answer:
Maslow’s Need Hierarchy Theory of Motivation:
Abraham Maslow’s Need Hierarchy Theory is considered fundamental to understanding of motivation. His theory was based on human needs. Various human needs are:
1. Physiological Needs:
These are the basic needs which include food, clothes, hunger, thirst, shelter, sleep and sex. If physiological needs are not satisfied, the higher level needs will not be emerged.

2. Safety/Security Needs:
These needs provide security and protection from physical and emotional harm. These needs include job security, stability of income, pension plans, etc.

3. Social Needs:
These needs refer to affection, sense of belongingness, acceptance and friendship. Informal organisation helps to satisfy the social needs of an individual.

4. Esteem Needs:
These include factors such as self-respect, autonomy status, recognition and attention.

5. Self Actualisation Needs:
It is the highest level of need in the hierarchy. Self actualisation is the need to maximise one’s potential, whatever it may be. These needs include growth, self-fulfilment and achievement of goals.

Question 8.
Explain the importance of communication in a business organisation.
Answer:
Importance of Communication:
1. Acts as basis of co-ordination: Communication acts as the basis of co-ordination.

2. Helps in smooth working of an enterprise: It is only communication, which makes smooth working of an enterprise possible.

3. Acts as basis of decision making: Comm Plication provides needed irftormation for decision making.

4. Increases managerial efficiency: Communication lubricates the entire organisation and keeps the organisation at work with efficiency.

5. Promotes co-operation and industrial peace: Communication promotes co-operation and mutual understanding between the management and workers.

6. Establishes effective leadership: Commu-nication is the basis of leadership. Effective communication helps to influence subordinates.

7. Boosts morale and provides motivation: An efficient system of communication enables management to motivate, influence and satisfy the subordinates. It helps to boost morale of employees and managers.

Question 9.
Explain various communication networks.
Answer:
Communication network:
It refers to the pattern through which members of work groups communicate.
The pattern through which communication flows within the organisation is generally indicated through communication network. Some of the communication networks are:

1. Single Chain:
This network exists between a supervisor and his subordinates. Here communication flows from every superior to his subordinate through single chain.

2. Wheel:
In wheel network, all subordinates under one superior communicate through him only. The subordinates are not allowed to communicate among themselves.

3. Circular:
In circular network, the communication moves in a circle. Each person can communicate with his adjoining two persons.

4. Free flow:
In this network, each person can communicate with others freely.

5. Inverted V:
In this network, a subordinate is allowed to communicate with his immediate superior as well as his superior’s superior.

Question 10.
Explain the forms of communication
Answer:
Communication may be classified as follows

Question 11.
“Leadership is considered as the most important element of the directing function of the management.” In the light of this statement, explain the importance of leadership.
Answer:
Importance of Leadership:

1. A leader inspires, supports and influences the behaviour of subordinates to achieve the organisational objective.
2. Effective leadership helps to achieve a harmonious relation between the management and subordinates.
3. Leadership helps to create job satisfaction among employees by providing good working condition.
4. A good leader persuades the people to accept and carry out the desired change.
5. A leader handles conflicts effectively.
6. Leader provides training to their subordinates.
7. Effective leadership helps to increase efficiency and productivity.

Question 12.
“To be successful as a manager one must be a good leader”. Outline the qualities of a good leader in the light of the above statement.
Answer:
Qualities of Good Leader:

• Physical Features: Physical features like height, weight, health, appearance determine the physical personality of a leader.
• Knowledge: A good leader should have required knowledge and competence.
• Honesty: A leader should possess high level of honesty.
• Initiative: A leader should have courage and initiative.
• Communication Skills: A leader should have the capacity to clearly explain the ideas.
• Motivation Skills: The leader should have the ability to motivate the subordinates by satisfying their needs.
• Self Confidence: A leader should have high level of self confidence.

Question 13.
What are the points to be kept in mind while communicating a message?
Answer:
Measures to overcome barriers to communication:

1. The entire problem to be communicated should be studied in depth, analysed and stated in such a manner that it is clearly conveyed to subordinates.
2. Communication must be according to the education and understanding levels of subordinates.
3. Before communicating.the message, it is better to consult with others.
4. The contents of the message, tone, language used, etc. are important aspects of effective communication.
5. While conveying message to others, it is better to know the interests and needs of the receiver.
6. Ensure proper feedback.
7. Manager should be a good listener.

Plus Two Business Studies Directing Eight Mark Questions and Answers

Question 1.
Mr. Radha Krishnan, the personal manager of an organisation recently conducted a survey among the employees of his organisation to identify theirdesires and needs. The needs and desires of the employees identified by him are listed below.

• Love and affection
• Accepted by one peer’s
• Self fulfilment
• Better clothing and shelter
• Economic stability
• Security in old age
• Protection against accidents
• Dignity

1. Arrange these needs and desires under the frame-work of Maslow’s theory.
2. What are the important features of this theory?

Answer:
1. Maslow’s Need Hierarchy Theory of Motivation:
Abraham Maslow’s Need Hierarchy Theory is considered fundamental to understanding of motivation. His theory was based on human needs. Various human needs are:
1. Physiological Needs:
These are the basic needs which include food, clothes, hunger, thirst, shelter, sleep and sex. If physiological needs are not satisfied, the higher level needs will not be emerged.

2. Safety/Security Needs:
These needs provide security and protection from physical and emotional harm. These needs include job security, stability of income, pension plans, etc.

3. Social Needs:
These needs refer to affection, sense of belongingness, acceptance and friendship. Informal organisation helps to satisfy the social needs of an individual.

4. Esteem Needs:
These include factors such as self-respect, autonomy status, recognition and attention.

5. Self Actualisation Needs:
It is the highest level of need in the hierarchy. Self actualisation is the need to maximise one’s potential, whatever it may be. These needs include growth, self-fulfilment and achievement of goals.

2. important features of this theory:
1. Physiological needs – Better clothing and shelter Economic stability
2. Safety needs – Security in old age Protection against accidents
3. Social needs – Love and affection Accepted by one peer’s
4. Esteem needs – Dignity
5. Self actualisation – Self fulfilment needs

Question 2.
“Direction is the heart of management”.

1. Do you agree?
2. Give reasons in support of your answer.

Answer:
1. Directing:
Directing refers to the process of instructing, guiding, counselling, motivating and leading people in the organisation to achieve its objectives.

2. Importance of Directing:

• Directing helps to initiate action by people in the organisation towards attainment of desired objectives.
• Directing integrates employees’ efforts in the organisation in such a way that every individual effort , contributes to the organizational performance.
• Directing guides employees to fully realise their potential and capabilities by motivating and providing effective leadership.
• Directing facilitates introduction of needed changes in the organization.
• Effective directing helps to bring stability and balance in the organization.

Question 3.
“Supervision is needed in all organizations so as to get the best out of the employees”

1. Do you agree?
2. Explain.

Answer:
1. Supervision:
Supervision means overseeing the subordinates at work. Supervision is instructing, guiding and controlling the workforce with a view to seethatthey are working according to plans, policies, programmes and instructions.

2. Importance of Supervision:

• A good supervisor acts as a guide, friend and philosopher to the workers.,
• Supervisor acts as a link between workers and management. It helps to avoid misunderstandings and conflicts among the management and workers.
• Supervisor provides good On the Job training to the workers and employees.
• A supervisor with good leadership qualities can build up high morale among workers.
• A good supervisor analyses the work performed and gives feedback to the workers.
• Supervisors help to maintains harmony among workers.

Question 4.
“Motivation means a process of stimulating people to action to accomplish desired goals.”

1. Do you agree with this statement?
2. Explain.

Answer:
1. Motivation:
Motivation is the process of stimulating people to action to accomplish desired goals. Motivation depends upon satisfying needs of people.

2. Importance of Motivation:

• Motivation helps to improve performance levels of employees as well as the organisation.
• Motivation helps to change negative attitudes of employee to positive attitudes.
• Motivation helps to reduce employee turnover.
• Motivation helps to reduce absenteeism in the organisation.
• Motivation helps managers to introduce changes smoothly.

Students can Download Chapter 6 Staffing Questions and Answers, Plus Two Business Studies Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus Two Business Studies Chapter Wise Questions and Answers Chapter 6 Staffing

Plus Two Business Studies Staffing One Mark Questions and Answers

Question 1.
Which functions of management helps in obtaining right people and putting them on the right jobs.
Answer:
Staffing.

Question 2.
Name the process concerned with searching for prospective candidates for vacant job position.
Answer:
Recruitment.

Question 3.
Name the function which is concerned with discovering the sources of manpower required and tapping these sources.
Answer:
Recruitment.

Question 4.
It is the process of searching for prospective employees and stimulating them to apply for jobs in the organisation Identify the concept.
Answer:
Recmitment.

Question 5.
Selection starts where ends.
Answer:
Recruitment.

Question 6.
Which among the following is not a case of external recruitment?
(a) Advertisement
(b) Transfer
(c) Employment
(d) Field trip
Answer:
(b) Transfer.

Question 7.
Since more candidates will be rejected than hired through this process, it is described as a negative process. Identify the process?
Answer:
Selection.

Question 8.
Shifting of an employee from one position to another without changes in status and remuneration is called
Answer:
Transfer.

Question 9.
“It is the breaking up of a job into basic elements or operations and studying in details each of the operations to know the nature and characteristics of the job.” This is called; (job specification, job analysis, job identification, job study)
Answer:
Job analysis.

Question 10.
The management of XY Ltd., asks the labour unions to provide a list of candidates for the vacancy of two persons in the office. Identify the source and explain.
Answer:
External sources of recruitment.

Question 11.
The final year students of National Institute of Management were sent to various industrial concerns for practical training. Identify the type of training and state its relevance.
Answer:
Internship training.

Question 12.
Vestibule training is given
Answer:
Outside the job; inside the factory.

Question 13.
Vijay chemicals selected 15 workers for their chemical plant. They intend to train the workers without effecting normal work. Suggest the best method of training.
Answer:
Vestibule training.

Question 14.
This is a method of training where business units make agreement with professional and vocational institutes to provide practical experience. Identify the method of training mentioned here.
Answer:
Internship training.

Question 15.
Face to face contact between the employer and candidate is called
Answer:
Interview

Question 16.
Which one of the following functions is not related with staffing function?
(a) Recruitment of employees
(b) Selection of employees
(c) Compensation of employees
(d) Motivation of employees
Answer:
(d) Motivation of employees

Question 17.
Mr. Sajan is working as Human Resource Manager of an automobile manufacturing unit. One of the following combinations represents his functions. Identify it.
(a) Recruitment, branding, dividend decision
(b) Selection, training, recruitment
(c) Selection, recruitment, marketing
(d) Training, pricing, promotion
Answer:
(b) Selection, training, recruitment

Question 18.
Mr. Abraham seeks new employees for his business. Name any two external sources of recruitment.
Answer:

1. Advertising
2. Empolyment exchange

Question 19.
Mr. Mohan Kumar, the HR Manager of Global Bank Ltd. wants to appoint 50 computer operators for their different branches in Kerala from internal sources. Name any two internal sources forthe recruitment.
Answer:

1. Transfer
2. Promotion

Question 20.
The cheapest method of recruitment is
Answer:
Internal sources of recruitment.

Question 21.
The training method of shifting employee from one job to another is called
Answer:
Job rotation.

Question 22.
Which one of the following is not an On the Job Training method?
(a) Apprenticeship training
(b) Case studies
(c) Computer modelling
(d) Programme instructions
Answer:
(a) Apprenticeship training

Question 23.
is a measure of individual’s potential for learning new skills.
Answer:
Aptitude test.

Question 24.
Which among the following statements are fake?
(a) Training is job oriented process and development is career oriented process.
(b) Internal sources of recruitment motivates the existing staff.
(c) Recruitment is a positive process.
(d) None of the above.
Answer:
(d) None of the above.

Question 25.
Match the following.

Answer:
a → b
b → c
c → a

Plus Two Business Studies Staffing Two Mark Questions and Answers

Question 1.
What do you mean by staffing?
Answer:
Meaning:
Staffing is concerned with determining the manpower requirement of enterprise and includes functions like recruitment, selection, placement, promotion, training, growth and development and performance appraisal of employees in the organization.

Question 2.
Staffing is an important function of management in all organisations. Explain, in brief, any 4 reasons.
Answer:
Importance of Staffing

1. Helps in discovering and obtaining competent personnel for various jobs.
2. Makes for higher performance, by putting right person on the right job.
3. Ensures continuous survival and growth of the enterprise.
4. Helps to ensure optimum utilization of human resources.
5. Improves job satisfaction and morale of employees.

Question 3.
What is recruitment?
Answer:
It is the process of searching for prospective employees and stimulating them to apply for the job in the organisation.

Question 4.
What is selection?
Answer:
Selection:
Selection is the process of identifying and choosing the best person out of a number of prospective candidates for a job.

Plus Two Business Studies Staffing Three Mark Questions and Answers

Question 1.
Why recruitment is regarded as a Positive Process and selection is a negative process.
Answer:
Recruitment is Positive Process because it is concerned with attracting qualified and competent individuals to apply for a job while selection is choosing the best among them and rejecting the unsuitable candidates. So selection is regarded as a negative process.

Question 2.
What is training?
Answer:
Training:
Training is any process by which the aptitudes, skills and abilities of employees to perform specific jobs are increased.

Question 3.
You know that tests are conducted to know the level of ability, knowledge, interest, aptitude, etc. of a particular candidate. Can you suggest an appropriate test for the following and justify.

1. Data entry operator
2. KSRTC driver
3. Personnel manager

Answer:

1. Trade test
2. Trade test
3. Interest test

Question 4.
What are the functions of Human Resource Management?
Answer:
Functions of Human Resource Management

1. Recruitment, i.e., search for qualified people.
2. Analysing jobs, collecting information about jobs to prepare job descriptions.
3. Developing compensation and incentive plans.
4. Training and development of employees.
5. Maintaining labour relations
6. Handling grievances and complaints.
7. Providing for social security and welfare of employees.
8. Maintaining relation with trade unions.

Plus Two Business Studies Staffing Four Mark Questions and Answers

Question 1.
Matha Ltd. invited applications for 20 sales representatives through an advertisement in a daily newspaper. 106 applications were received out of which nine were rejected due to lack of sufficient experience and qualification. The remaining applicants have undergone a written test and an interview. After this, the most efficient 20 applicants were selected. Identify the two major activities processes mentioned in the above situation and also differentiate between them.
Answer:
The above activities are recruitment and selection. The following are the difference between them.

Question 2.
Excel Sugars is a newly established sugar company where a large number of employees are required for different jobs.

1. As a commerce student can you say which source of recruitment is suitable?
2. Why?

Answer:
Excel Sugars is a newly established business organisation. So Internal sources of recruitment is not possible. The company can select employees from various external sources. External sources of Recruitment
a. External Sources:
Selection of employees from outside the enterprise is known as external recruitment.
The important external sources of recruitment are:

1. Direct Recruitment:
Under the direct ‘ recruitment, a notice is placed on the notice-board of the enterprise specifying the details of the jobs available. Job seekers assemble outside the premises of the organisation on the specrfied date and selection is done on the spot. It is suitable for filling casual vacancies.

2. Casual callers:
Many reputed business organisations keep a database of unsolicited applicants in their office. These list can be used for recruitment.

3. Advertisement:
Advertisement in newspapers or trade and professional journals is generally used when a wider choice is required.

4. Employment Exchange:
Employment exchanges keep records of job seekers and will be supplied to business concern on the basis of their requisition.

5. Placement Agencies and Management Consultants:
These agencies compile bio-data of a large number of candidates and recommend suitable names to their clients.

6. Campus Recruitment:
Business enterprises may conduct campus recruitment in educational institutions for selecting young and talented candidates.

7. Recommendations of Employees:
Applicants introduced by present employees, ortheirfriends and relatives may prove to be a good source of recruitment.

8. Labour Contractors:
Labour contractors maintain close contacts with labourers and they can provide the required number of unskilled workers at short notice.

9. Web Publishing:
There are certain websites specifically designed and dedicated forthe purpose of providing information to the job seekers.

Question 3.
Classify the following as internal and external sources of recruitment

1. Advertisement
2. Transfer
3. Campus recruitment
4. Promotion
5. Employment Exchange
6. Job Contractors

Answer:
Internal sources of recruitmentTransfer, Promotion. External sources of recruitment – Advertisement, Campus recruitment, Employment exchange, Job contractors.

Question 4.
In a classroom debate, Jith argues that recruitment and selection are same. Anoop argues that both are different.

1. Whom do you support? Give justification.
2. If you are supporting Anoop, which one comes first?

Answer:
1. We can support the argument of Anoop Staffing Process.
a. Manpower planning:
It is concerned with forecasting the future manpower needs of the organisation, i.e. finding outnumber and type of employees need by the organisation in future.

b. Recruitment:
Recruitment may be defined as the process of searching for prospective employees and stimulating them to apply for jobs in the organisation.

c. Selection:
Selection is the process of selecting the most suitable candidates from a large number of applicants.

d. Placement and Orientation:
Placement refers to putting the right person on the right job. Orientation is introducing the selected employee to other employees and familiarising him with the rules and policies of the organisation.

e. Training and Development:
The process of training helps to improve the job knowledge and skill of the employees. It motivates the employees and improve their efficiency.

f. Performance Appraisal:
Performance appraisal means evaluating an employee’s current and past performance as against certain predetermined standards.

g. Promotion and Career Planning:
Promotion means movement of an employee from his present job to a higher level job.

h. Compensation:
Compensation refers to all forms of pay or rewards going to employees. It may be in the form of direct financial payments like wages, salaries, commissions and indirect payments like employer paid insurance and vacation.

Selection:
Selection is the process of identifying and choosing the best person out of a number of prospective candidates for a job.

2. Recruitment is the first process.

Question 5.
Explain any four methods of Off the Job Training.
Answer:
Off the Job Method:
It refers to those methods under which an individual is provided training away from the work place. It means learning before doing.
The important Off the Job Methods are:

a. Classroom Lectures/Conferences:
The lecture approach is well adapted to convey specific information such as rules, procedures or methods. The use of audio-visuals can often make a formal classroom.

b. Films:
They can provide information and demonstrate skills.

c. Case Study:
Trainee studies the cases to determine problems, analyses causes, develop alternative solutions and select the best solution to implement.

d. Computer Modelling:
It stimulate the work environment by programming a computer to imitate the realities of the job and allows learning to take place without the risk or high cost.

e. Vestibule Training:
Under this method, separate training centres are set up to give training to the new employees. Actual work environment is created in that centre and employees used the same material, equipment, etc. which they use while doing the actual job.

f. Programmed Instruction:
Here information is broken into meaningful units and these units are arranged in a proper way to form a logical and sequential learning package.

Plus Two Business Studies Staffing Five Mark Questions and Answers

Question 1.
Distinguish between internal sources and external sources of recruitment.
Answer:

Question 2.
Identify the following types of training.

1. Its purpose is to familiarize the existing employees with the latest methods.
2. The employee has to rotate from one job to another.
3. Emphasis is given to learning by doing.
4. A large number of persons are to be trained at the same time for the Same kind of work.
5. It is for introducing a new employee to the organisation.

Answer:

1. Refresher Training
2. Job Rotation
3. Apprenticeship Training
4. Vestibule Training
5. Induction Training

Question 3.
List down the advantages of training to the employees.
Answer:
Benefits to the Employee

1. Training helps in securing promotion and career growth.
2. Increased performance by the individual helps him to earn more.
3. Training helps to reduce the chances of accident and wastages.
4. Training increases the satisfaction of employees

Question 4.
Explain the importance of staffing in management.
Answer:
Importance of Staffing

1. Helps in discovering and obtaining competent personnel for various jobs.
2. Makes for higher performance, by putting right person on the right job.
3. Ensures continuous survival and growth of the enterprise.
4. Helps to ensure optimum utilization of human resources.
5. Improves job satisfaction and morale of employees.

Question 5.
Training helps to increase the efficiency of employees Explain.
Answer:
1. On the Job Method:
Under this method, the employee is given training when he is on the job. It means learning while doing.
The important On the Job Methods are:

a. Apprenticeship Programme:
Under apprenticeship training, a trainee is put under the supervision of a master worker.

b. Coaching:
In this method, the superior guides and instructs the trainee as a coach.

c. Internship Training:
It is a joint programme of training in which vocational and professional institutes enter into an agreement with business enterprises for providing practical knowledge to its students.

d. Job Rotation:
Here the trainee is transferred from one job to another job or from one department to another department so that he can learn the working of various sections.

2. Off the Job Method:
It refers to those methods under which an individual is provided training away from the workplace. It means learning before doing.
The important Off the Job Methods are:

a. Classroom Lectures/Conferences:
The lecture approach is well adapted to convey specific information such as rules, procedures or methods. The use of audio-visuals can often make a formal classroom.

b. Films:
They can provide information and demonstrate skills.

c. Case Study:
Trainee studies the cases to determine problems, analyses causes, develop alternative solutions and select the best solution to implement.

d. Computer Modelling:
It stimulate the work environment by programming a computer to imitate the realities of the job and allows learning to take place without the risk or high cost.

e. Vestibule Training:
Under this method, separate training centres are set up to give training to the new employees. Actual work environment is created in that centre and employees used the same material, equipment, etc. which they use while doing the actual job.

f. Programmed Instruction:
Here information is broken into meaningful units and these units are arranged in a proper way to form a logical and sequential learning package.

Plus Two Business Studies Staffing Eight Mark Questions and Answers

Question 1.
Explain briefly steps involved in staffing.
Answer:
Staffing Process
1. Manpower planning:
It is concerned with forecasting the future manpower needs of the organisation, i.e. finding outnumber and type of employees need by the organisation in future.

2. Recruitment:
Recruitment may be defined as the process of searching for prospective employees and stimulating them to apply for jobs in the organisation.

3. Selection:
Selection is the process of selecting the most suitable candidates from a large number of applicants.

4. Placement and Orientation:
Placement refers to putting the right person on the right job. Orientation is introducing the selected employee to other employees and familiarising him with the rules and policies of the organisation.

5. Training and Development:
The process of training helps to improve the job knowledge and skill of the employees. It motivates the employees and improve their efficiency.

6. Performance Appraisal:
Performance appraisal means evaluating an employee’s current and past performance as against certain predetermined standards.

7. Promotion and Career Planning:
Promotion means movement of an employee from his present job to a higher level job.

8. Compensation:
Compensation refers to all forms of pay or rewards going to employees. It may be in the form of direct financial payments like wages, salaries, commissions and indirect payments like employer-paid insurance and vacation.

Question 2.
Aparna textiles decided to open a new Branch in Ernakulam. For the new showroom, they estimated 3 cashiers, 30 salesmen, 10 supervisors.

1. As a commerce student can you suggest the important sources for recruiting for the above vacancies?
2. Explain its advantages and disadvantages.

Answer:
a. Internal Sources:
It refers to the recruitment for jobs from within the organisation. It includes:
1. Transfer:
It involves shifting of an employee from one job to another without change in responsibility or compensation.

2. Promotion:
It refers to shifting of a person from lower position to a higher position carrying higher status, responsibility and more salary.

b. External Sources:
Selection of employees from outside the enterprise is known as external recruitment.
The important external sources of recruitment are:

1. Direct Recruitment:
Under direct recruitment, a notice is placed on the notice-board of the enterprise specifying the details of the jobs available. Job seekers assemble outside the premises of the organisation on the specified date and selection is done on the spot. It is suitable for filling casual vacancies.

2. Casual callers:
Many reputed business organisations keep a database of unsolicited applicants in their office. This list can be used for recruitment.

3. Advertisement:
Advertisement in newspapers or trade and professional journals is generally used when a wider choice is required.

4. Employment Exchange:
Employment exchanges keep records of job seekers and will be supplied to business concern on the basis of their requisition.

5. Placement Agencies and Management Consultants:
These agencies compile bio-data of a large number of candidates and recommend suitable names to their clients.

6. Campus Recruitment:
Business enterprises may conduct campus recruitment in educational institutions for selecting young and talented candidates.

7. Recommendations of Employees:
Applicants introduced by present employees, or their friends and relatives may prove to be a good source of recruitment.

8. Labour Contractors:
Labour contractors maintain close contacts with labourers and they can provide the required number of unskilled workers at short notice.

9. Web Publishing:
There are certain websites specifically designed and dedicated for the purpose of providing information to the job seekers.

Question 3.
Mr. Tom the newly appointed personnel manager of Hindustan Ltd. was given full responsibility for hiring people for the company to fill various positions in the production department.

1. He is confused as to which recruitment sources he would use?
2. Can you help him in this regard?

Answer:
a. Internal Sources:
It refers to the recruitment for jobs from within the organisation It includes:
1. Transfer:
It involves shifting of an employee from one job to another without change in responsibility or compensation.

2. Promotion:
It refers to shifting of a person from lower position to a higher position carrying higher status, responsibility and more salary.

b. External Sources:
Selection of employees from outside the enterprise is known as external recruitment.
The important external sources of recruitment are:

1. Direct Recruitment:
Under the direct ‘ recruitment, a notice is placed on the notice-board of the enterprise specifying the details of the jobs available. Job seekers assemble outside the premises of the organisation on the specified date and selection is done on the spot. It is suitable for filling casual vacancies.

2. Casual callers:
Many reputed business organisations keep a database of unsolicited applicants in their office. This list can be used for recruitment.

3. Advertisement:
Advertisement in newspapers or trade and professional journals is generally used when a wider choice is required.

4. Employment Exchange:
Employment exchanges keep records of job seekers and will be supplied to business concern on the basis of their requisition.

5. Placement Agencies and Management Consultants:
These agencies compile bio-data of a large number of candidates and recommend suitable names to their clients.

6. Campus Recruitment:
Business enterprises may conduct campus recruitment in educational institutions for selecting young and talented candidates.

7. Recommendations of Employees:
Applicants introduced by present employees, or their friends and relatives may prove to be a good source of recruitment.

8. Labour Contractors:
Labour contractors maintain close contacts with labourers and they can provide the required number of unskilled workers at short notice.

9. Web Publishing:
There are certain websites specifically designed and dedicated for the purpose of providing information to the job seekers.

Question 4.
The banking recruitment board gave an advertisement for selection of candidates to various posts in the bank. A large number of applications has been received. Can you suggest the various steps that have to be followed by the board to choose the right candidates?
Answer:
Process of Selection
1. Preliminary Screening:
Preliminary screening helps the manager to eliminate unqualified job seekers.

2. Selection Tests:
Various tests are conducted to know the level of ability, knowledge, interest, aptitude, etc. of a particular candidate. The various types of tests are:

1. Intelligence Tests: This is one of the important psychological tests used to measure the level of intelligence quotient (IQ) of an individual.
2. Aptitude Test: It is a measure of an individual’s potential for learning new skills.
3. Personality Tests: Personality tests provide clues to a person’s emotions, reactions, maturity and value system, etc.
4. Trade Test: These tests measure the existing skills of the individual.
5. Interest Tests: Interest tests are used to know the pattern of interests or involvement of a person.

3. Employment Interview:
Interview is a formal, in-depth conversation conducted to evaluate the applicant’s suitability for the job.

4. Reference and Background Checks:
Many employers request names, addresses, and telephone numbers of references for the purpose of verifying information and, gaining additional information on an applicant.

5. Final Selection:
The final decision has to be made from among the candidates who pass the tests, interviews and reference checks.

6. Medical Examination:
After selection, the candidates are required to appear for a medical examination for ensuring that he is physically fit for the job.

7. Job Offer:
After a candidate has cleared all the hurdles in the selection procedure, he is formally appointed through an order. It contains the terms and conditions of the employment, pays scale, joining time, etc.

8. Employment Contract:
Basic information that should be included in a written contract of employment are job title, duties, responsibilities, date of joining, pay and allowances, hours of work, leave rules, disciplinary procedure, work rules, termination of employment, etc.

Students can Download Chapter 8 Controlling Questions and Answers, Plus Two Business Studies Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus Two Business Studies Chapter Wise Questions and Answers Chapter 8 Controlling

Plus Two Business Studies Controlling One Mark Questions and Answers

Question 1.
Which function of management consists of the following elements?

1. Determination of standards
2. Measuring performance
3. Comparing performance with standards
4. Taking corrective actions

Answer:
Controlling

Question 2.
The first step in the control process which a manager has to do is ………………………
Answer:
Setting standards

Question 3.
If managers try to control everything, they may end up controlling nothing. Identify the relevant management principle underlying this statement.
Answer:
Management by exception (MBE)

Question 4.
Identify the principle which indicates that only significant deviations from standards require the attention of management.
Answer:
Management by Exception (MBE)

Question 5.
An efficient control system helps to
(a) Accomplish organisational objectives
(b) Boost employee morale
(c) Judge accuracy of standards
(d) All of the above
Answer:
(d) All of the above

Question 6.
Pick out one statement which is not limitation of controlling.
(a) Standards cannot be fixed properly.
(b) Controlling has little control on external factors.
(c) It is costly and time-consuming process.
(d) Controlling is applicable at all levels of management.
Answer:
(d) Controlling is applicable at all levels of management.

Question 7.
Choose the right statement.
(a) Planning – Staffing are the two sides of the same coin.
(b) Planning – Controlling are the two sides of the same coin.
(c) Organising – Staffing are the two sides of the same coin.
(d) Directing-Planning are the two sides of the same coin.
Answer:
(b) Planning – Controlling are the two sides of the same coin.

Question 8.
Write two examples for modern controlling techniques.
Answer:

• Return on Investment method
• PERT & CPM

Question 9.
Choose the right tool for controlling.
(a) Critical Path Method (CPM)
(b) Common Policy Method (CPM)
(c) Production Evaluation and Review Technique (PERT)
(d) Personality Evaluation and Rare Technique (PERT)
Answer:
(a) Critical Path Method (CPM)

Question 10.
Return on Investment = ………………
Answer:
\(\frac{\text { Net Income }}{\text { Total Investment }}\)

Question 11.
Comparing the values in a financial statement is called ……………..
(a) Return on Investment
(b) Ratio analysis
(c) Responsibility Accounting
(d) PERT & CPM
Answer:
(b) Ratio Analysis

Question 12.
Entrusting the responsibility of expenses to different departments is called …………………
Answer:
Responsibility accounting

Question 13.
Modem controlling techniques used to both planning and controlling are ……………………
Answer:
PERT & CPM

Question 14.
What is management audit?
(a) Evaluate the efficiency of management.
(b) Analyse the financial statement by using ratios.
(c) Charge the expenses to departments and evaluate the responsibilities.
(d) No profit No loss.
Answer:
(a) Evaluate the efficiency of management.

Question 15.
Comparing Investment & Profit is ………………
Answer:
Return on Investment

Question 16.
Traditional method of controlling which helps to motivate employees is …………………..
Answer:
Personal observation

Question 17.
……………… is a network technique useful in planning and controlling.
Answer:
Critical Path Method (CPM)

Question 18.
B.E.P. =
Answer:
Break Even Point = \(\frac{\text { Fixed cost }}{\text { Selling Price per Unit – Variable Cost per Unit }}\)

Question 19.
…………………. is a technique of managerial control in which standards are expressed in terms of money.
Answer:
Budgetary Control

Question 20.
………………. is a computer based managerial control technique.
Answer:
Management Information System (MIS)

Plus Two Business Studies Controlling Two Mark Questions and Answers

Question 1.
What is the significance of standard?
Answer:
Helpful in analysing deviation. It is compulsary to fix a standard in order to compare the actual performance.

Question 2.
What is deviation in controlling?
Answer:
It is the difference between actual performance and standard performance.

Question 3.
Rearrange the following in a correct sequence of steps in controlling.

Answer:

Question 4.
In the controlling process only these deviations from standard which seem exceptionally are brought to the attention of top management. Identify the relevant principle behind this.
Answer:
Management by exception / Control by exception.

Plus Two Business Studies Controlling Three Mark Questions and Answers

Question 1.
What is meant by budgetary control?
Answer:
Budgetary Control:
Budgetary control is a technique of managerial control in which all operations are planned in advance in the form of budgets and actual results are compared with budgetary standards.

Plus Two Business Studies Controlling Four Mark Questions and Answers

Question 2.
“They are the two blades of a scissor; one cannot work without the other”.

1. Identify the management functions referred to this context.
2. Explain the nature of relationships between these managerial functions.

Answer:
1. I agree with this statement.

2. Relationship between Planning and Controlling:

1. Planning and control are interdependent and inseparable functions of management.
2. Planning is a prerequisite for controlling.
3. Planning initiates the process of management and controlling complete the process.
4. Planning is prescriptive where as controlling is evaluative.
5. Planning and controlling are both backward looking as well as forward looking functions.
6. Planning based on facts makes controlling easier and effective.

Question 3.
Planning and control are interdependent and inseparable functions of management.

1. Do you agree with this statement?
2. Explain.

Answer:
1. I agree with this statement.

2. Relationship between Planning and Controlling:

• Planning and control are interdependent and inseparable functions of management.
• Planning is a prerequisite for controlling.
• Planning initiates the process of management and controlling complete the process.
• Planning is prescriptive where as controlling is evaluative.
• Planning and controlling are both backward looking as well as forward looking functions.
• Planning based on facts makes controlling easier and effective.

Question 4.
‘Planning is useless without control and control is aimless without plans.’

1. Do you agree?
2. Explain.

Answer:
1. I agree with this statement.

2. Relationship between Planning and Controlling:

1. Planning and control are interdependent and inseparable functions of management.
2. Planning is a prerequisite for controlling.
3. Planning initiates the process of management and controlling complete the process.
4. Planning is prescriptive where as controlling is evaluative.
5. Planning and controlling are both backward looking as well as forward looking functions.
6. Planning based on facts makes controlling easier and effective.

Plus Two Business Studies Controlling Five Mark Questions and Answers

Question 1.
Distinguish between Traditional & Modem Controlling Techniques.

1. Return on Investment
2. Ratio Analysis
3. Budgetery Control
4. Management Audit
5. Statistical Data
6. Responsibility Accounting
7. Break Even Analysis
8. PERT & CPM
9. Personal Observation

Answer:

Question 2.
Explain the limitations of Controlling.
Answer:
Limitations of Controlling:

1. Difficulty in setting quantitative standards:
Control system loses some of its effectiveness when standards cannot be defined in quantitative terms.

2. Little control on external factors:
Generally an enterprise cannot control external factors such as government policies, technological changes, competition, etc.

3. Resistance from employees:
Control is often resisted by employees. They see it as a restriction on their freedom.

4. Costly affair:
Control is a costly affair as it involves a lot of expenditure, time and effort.

Question 3.
List down the importance of Controlling.
Answer:
Importance of Controlling:

1. Accomplishing organisational goals:
The controlling function measures progress towards the organisational goals and brings to light the deviations, if any, and indicates corrective action.

2. Judging accuracy of standards:
A good control system enables management to verify whether the standards set are accurate.

3. Making efficient use of resources:
By exercising control, a manager seeks to reduce wastage of resources.

4. Improving employee motivation:
A good control system motivates the employees and helps them to give better performance.

5. Ensuring order and discipline:
Controlling creates an atmosphere of order and discipline in the organisation.

6. Facilitating co-ordination:
An efficient system of control helps to co-ordinate all the activities in the organisation.

Question 4.
Explain the different Techniques of Managerial Control.
Answer:
Techniques of Managerial Control:
1. Traditional Techniques:

a. Personal Observation:
It creates psychological pressure on the employees to perform well as they are aware that they are being observed personally on their job.

b. Statistical Reports:
Statistical analysis in the form of averages, percentages, ratios, correlation, etc. present useful information to the managers regarding performance of the organisation.

c. Break Even Analysis:
Break even analysis is a technique used by managers to study the relationship between costs, volume and profits. The sales volume at which there is no profit, no loss is known as break even point. It helps in estimating profits at different levels of activities.
B.E.P = \(\frac{F}{s-v}\)
F = Fixed cost
S = Selling price per unit
V = Variable cost per unit

d. Budgetary Control:
Budgetary control is a technique of managerial control in which all operations are planned in advance in the form of budgets and actual results are compared with budgetary standards.

2. Modem Techniques:

a. Return on Investment:
Return on Investment (ROI) can be used to measure overall performance of an organisation. It helps to know the invested capital has been used effectively for generating reasonable amount of return.

Return on investment = \(\frac{\text { Net Income }}{\text { Total Investment }}\)

b. Ratio Analysis:
Ratio Analysis refers to analysis of financial statements through computation of ratios.

c. Responsibility Accounting:
Responsibility accounting is a system of accounting in which different sections, divisions, and departments of an organisation are set up as ‘Responsibility Centres’. The head of the centre is responsible for achieving the target set for his centre. E.g. Cost centre, Revenue centre, Profit centre, Investment centre, etc.

d. Management Audit:
Management audit may be defined as evaluation of the functioning, performance, and effectiveness of management of an organisation.

e. PERT and CPM:
PERT (Programme Evaluation and Review Technique) and CPM (Critical Path Method) are important network techniques useful in planning and controlling.

Plus Two Business Studies Controlling Eight Mark Questions and Answers

Question 1.
Controlling is a systematic function of management. Explain.
Answer:
Controlling Process:
Controlling is a systematic process involving the following steps.

• Setting performance standards
• Measurement of actual performance
• Comparison of actual performance with standards
• Analysing deviations
• Taking corrective action

1. Setting Performance Standards:
Standards are the criteria against which actual performance would be measured. Standards can be set in both quantitative as well as qualitative terms.

2. Measurement of Actual Performance:
After establishing standards, the next step is measurement of actual performance. Performance should be measured in an objective and reliable manner.

3. Comparing Actual Performance with Standards:
This step involves comparison of actual performance with the standard. Such comparison will reveal the deviation between actual and desired results.

4. Analysing Deviations:
The deviations from the standards are assessed and analysed to identify the causes of deviations.

5. Taking Corrective Action:
The final step in the controlling process is taking corrective action. No corrective action is required when the deviations are within acceptable limits.

Students can Download Chapter 1 Electric Charges and Fields Questions and Answers, Plus Two Physics Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus Two Physics Chapter Wise Questions and Answers Chapter 1 Electric Charges and Fields

Plus Two Physics Electric Charges and Fields NCERT Text Book Questions and Answers

Question 1.
What is the force between two small charged spheres having charges of 2 × 10^-7C and 3 × 10^-7 C placed 30cm apart in air?
Answer:
Given q₁ = 2 × 10^-7C, q₁ = 3 × 10^-7 C
r = 30cm = 0.3m
Force of repulsion

Question 2.
When a glass rod is rubbed with a silk cloth, charges appear on both. A similar phenemenon is observed with many other pairs of bodies. Explain how this observation is consistent with the law of conservation of charge.
Answer:
When a glass rod is rubbed with silk, the charges developed on the glass rod and the piece of silk are equal and opposite. Similar is the case in other pair of bodies. So electric charge is neither be produced nor destroyed but simply transferred from one body to another, hence is consistent with the law of conservation of charge.

Question 3.
An electric dipole with dipole moment 4 × 10⁹ cm is aligned at 30° with the direction of a uniform electric field of magnitude 5 × 10⁴NC^-1. Calculate the magnitude of the torque acting on the dipole.
Answer:
Given
p = 4 × 10^-9cm, θ = 30°, E = 5 × 10⁴ NC^-1, τ = ?
Since τ = pEsinθ
= 4 × 10⁹ × 5 × 10⁴ × sin 30°
= 20 × 10^-5 × 1/2 = 10^-4Nm.

Question 4.
A Polythene piece rubbed with wool is found to have a negative charge of 3 × 10⁷C.

1. Estimate the number of electrons transferred from which to which?
2. Is there a transfer of mass from wool to polythene?

Answer:
1. Charge on one electron
∴ Number of electrons in the given charge

= 1.875 × 10¹² = 2 × 10¹²

2. Since woold gets negative charge on rubbing with polythene, wool must gain electrons from polythene.
∴ Ideally speaking there must be a transfer of mass due to transfer of electrons but since the mass of electron is very small, this transfer of mass may be negligible (=2 × 10¹⁸kg).

Question 5.
A uniformly charged conducting spheres of 2.4m diameter has a surface change density of 80.0m cm^-2.

1. Find the charge on the sphere.
2. What is the total electric flux leaving the surface of the sphere?

Answer:
Given σ = 80.0µcm^-2 = 80 × 10^-6cm^-2
D = 2.4m, r=1.2m
1. Charge on the sphere,
q = σ × 4πr²
= 80 × 10^-6 × 4 × 3.142 ×(1.2)²
= 1.45 × 10^-3C.

2. Electric flux,
Φ = \(\frac{q}{\varepsilon_{0}}=\frac{1.45 \times 10^{-3}}{8.854 \times 10^{-12}}\)
= 16 × 10⁸ NC^-1m²

Question 6.
An infinite line charge produces a field of 9 × 10⁴ NC^-1 at a distance of 2cm. Calculate the linear charge density.
Answer:
Given E = 9 × 10⁴ NC^-1, r = 2cm = 0.02m

Plus Two Physics Electric Charges and Fields One Mark Questions and Answers

Question 1.
A point charge Q is place at the center of a cube of side, i the electric flux emerging the cube is.

Answer:
(d) \(\frac{q}{\varepsilon_{0}}\)

Question 2.
A hollowing insulated conduction sphere is given a positive charge of 10p. what will be the electric field at the center of the sphere if its radius is 2 meters?
(a) 20 μ Cm^-2
(b) 5 Cm
(c) zero
(d) 8 Cm
Answer:
(a) 20 μ Cm^-2

Question 3.
A charge Q μ C is placed at the center of a cube, the flux coming out from each face will be.

Answer:
(a) \(\frac{Q}{6 \varepsilon_{0}} \times 10^{-6}\)
Explanation: For complete cube Φ = \(\frac{Q}{\varepsilon_{0}} \times 10^{-6}\)
For each face Φ = \(\frac{1}{6}\) \(\frac{Q}{\varepsilon_{0}} \times 10^{-6}\)

Question 4.
Pick the odd one out of the following based on electric field intensity.
(i) Point charge
(ii) Uniformly charged sphere
(iii) Uniformly charged cube
(iv) Uniformly charged sheet
Answer:
(iv) Uniformly charged sheet (The electric field does not depend on distance)

Question 5.
“Electrostatic force is medium dependent that is why NaCI dissolves in water” comment on this statement.
Answer:
Dielectric constant of water is 81. Hence the force between Na⁺ and cl^– reduces by 81 times.

Question 6.
Classify into true or false

1. In a charged conductor charges reside inside and out side the conductor
2. In a charged conductor net field is zero inside the conductor.

Answer:

1. False
2. True

Question 7.
Electrostatic force is a_____force
(i) Conservative
(ii) non conservative
(iii) medium independent
(iv) dissipative Conservative
Answer:
(i) Conservative

Plus Two Physics Electric Charges and Fields Two Mark Questions and Answers

Question 1.
It is safe to be inside a vehicle rather than outside, even when there is lightning and thunder. Comment on this.
Answer:
Inside a spherical shell electrical field is zero. This is called electrostatic shielding. Hence it is safe to be inside a vehicle rather than outside.

Question 2
There are two types of charges namely positive and negative.

1. List any two basic properties of electric charge.
2. Can a body have a charge of 0.8 × 1o^-19 C? Which basic property of electric charge is the reason for your answer?

Answer:
1. Quantization of electric charge. Conservation of electric charge.

2. No. According to quantisation of charge, total charge is Q = ne when ‘n’ is an intiger. Here
n = \(\frac{0.8 \times 10^{-19}}{1.6 \times 10^{-19}}\) = 0.5 n is a fractional value.

Plus Two Physics Electric Charges and Fields Three Mark Questions and Answers

Question 1.
A cubical iron block is given a charge of +40m C and placed in vacuum.

1. Give the direction of electric field at the centre of one face.
2. Calculate the net flux due to the charged cube through one face.
3. Will there be any change in the flux if it is placed underwater of dielectric constant 81. Justify.

Answer:
1. Normally outwards from the surface.
Total flux = \(\frac{40 \times 10^{-3}}{8.85 \times 10^{-12}}\) = 4.51 × 10⁹Nm²C^-1

2. Through one face = \(\frac{4.51 \times 10^{9}}{6}\) = 0.75 × 10⁹Nm²C^-1

3. Electric flux decreases because flux depends on permittivity of medium.

Question 2.
When a rubber sheet is rubbed with woolen carpet, the carpet is found to acquire a positive charge of 8 × 10^-7C
1. In the above process charging is by

• conduction
• friction
• induction
• polarization

2. Among Rubber shoe and woolen carpet which one acquire both mass and charge during rubbing? Explain.
Answer:
1. In the above process charging is by:

• Friction

2. Carpet is found to be positive body which means that electrons are lost from carpet to rubber shoe. Hence rubber shoe acquires charge and mass.

Question 3.
A glass rod rubbed with silk found to have acquired a positive charge 6.4 × 10^-7C.
1. In the above process charging is by

• Induction
• Conduction
• Friction
• Electromagnetic induction

2. Regarding above process which statement is false

• glass rod loss some mass
• silk gain negative charge but no mass
• Silk gain charge arid mass
• Total charge of the silk glass system is zero

3. Will the above process obey law of quantization of electric charge? Clarify your answer by finding numbers of electrons transferred to silk.
Answer:
1. In the above process charging is by:

• Friction

2. Regarding above process which statement is false:

• Silk gains charge and mass

3. yes
Number of electrons transferred to Silk,
n = \(\frac{q}{e}=\frac{6.4 \times 10^{-7}}{1.6 \times 10^{-19}}\) = 4 × 10¹²

Question 4.
In a NaCI molecule there is an attractive force between Na+ ion and Cl^– ion

1. Which law help us to find this attractive force? State the law.
2. State the law and write it’s mathematical form
3. Why NaCI molecule is easily soluble in water? [Hint;- Dielectric constant of water is 81]

Answer:
1. Coulombs law.

2. The force between two changes is directly proportional to product of their charges and inversely proportional to square of the distance between them. Force on q₁ due q₂.

3. Force between two charges depends on the medium in between them.
i.e. F = \(\frac{1}{4 \pi \varepsilon_{0} k} \frac{q_{1} q_{2}}{r^{2}}\)
For water molecule K=81. Hence the force between two charge in water decreases by 81 times. As result NaCl molecule is easily soluble in water.

Question 5.
There are two types of charges namely positive and negative.
1. List any two basic properties of electric charge. (1)

2. Can a body have a charge of 0.8 × 10^-19 C? Which basic property of electric charge is the reason for your answer? (1)

3. Name the basic property of electric charge that you can see in the equation. (1)
Rn₈₆ → P0₈₄ + He₂

Answer:
1. Quantization of electric charge. Conservation of electric charge.