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Kerala State Syllabus 10th Standard Biology Solutions Chapter 4 Keeping Diseases Away

Keeping Diseases Away Text Book Questions and Answers

Keeping Diseases Away Kerala Syllabus 10th Question 1.
What are the reasons forthe spread of diseases and list out practical suggestions to avoid such situations?
Answer:

Sslc Biology Chapter 4 Questions And Answers Question 2.
Expand the list by including pathogenic microorganisms?
Answer:

• Bacteria
• Virus
• Fungus
• Protozoa

Biology Class 10 Chapter 4 Notes Kerala Syllabus Question 3.
How are pathogens transmitted from one person to another?
Answer:

Communicable diseases:
Communicable diseases are caused by the invasion of pathogens into the body and are transmitted from one person to another.

Rat Fever (Leptospirosis)

Rat fever is a bacterial disease. Bacteria is a prokaryote. They enter the body and multiply through binary fission. The toxins produced by them destroy cells and cause disease.

Hss Live Guru 10th Biology Kerala Syllabus Question 4.
What are the measures to be taken to prevent the transmission of rat fever?
Answer:
For controlling diseases like rat fever, eliminate the vectors and take preventive medicines as per the directions of experts. Disease affected persons must undergo diagnostic tests to confirm their illness and should take proper medicines. Ensure personal hygiene and environmental hygiene.

Biology Class 10 Chapter 4 Kerala Syllabus Other Bacterial Diseases

Diphtheria:

Analyse the information and figure related to diphtheria and prepare a table

Tuberculosis:

Hsslive Guru 10th Biology Kerala Syllabus Question 5.
Mode of transmission of other bacterial diseases
Answer:

Hsslive Guru Biology 10th Kerala Syllabus Viral Diseases

Virus has the simple structure with a DNA or RNA molecule within a protein coat. Virus has no cell organelles as seen in normal cells. Hence virus multiplies by taking control over the genetic mechanism of the host cells. Viruses infect not only human beings but also plants, other animals and even bacteria.

Nipah Virus And Transmission Of The Disease:

Virus has the simple structure with a DNA or RNA molecule within a protein coat. Virus has no cell organelles as seen in normal cells. Hence virus multiplies by taking control over the genetic mechanism of host cells. Viruses infect human beings, plants, animals and bacteria

AIDS:
AIDS (Acquired Immuno Deficiency Syndrome) is a condition of gradual decrease of immunity by the destruction of lymphocytes by the infection of HIV. HIV enters the body and multiplies using the genetic mechanism of lymphocytes. Hence the number of lymphocytes decreases considerably and reduces the immunity of the body. Various other pathogens which enter the bod^ in such a situation make the condition of AIDS even more fatal

Class 10th Biology Chapter 4 Notes Kerala Syllabus Question 6.
What are the ways by which HIV spreads Write your inferences in science diary by analysing illustration?
Answer:

Sslc Biology Chapter 4 Notes Kerala Syllabus  Question 7.
How AIDS does not spread
Answer:

• By touch, shaking hands, coughing sneezing etc
• through insects like mosquitoes, house flies etc.
• by staying together and sharing food.
• Through the reception of blood and organs contaminated with HIV

Class 10 Biology Chapter 4 Notes Kerala Syllabus  Question 8.
Do we need to fear AIDS patients? What should be our attitude towards them Discuss?
Answer:
Unlike other diseases, AIDS can be completely prevented by taking right precautions. AIDS is not a communicable disease. Therefore AIDS virus will not be transferred through social contacts such as touching or sharing food, and water. It is transmitted by sexual contact transfusion of blood, using unsterilized needle and syringe, use of blade and the razor in the barbershops and mother to foetus. So show positive attitude towards AIDS patients. To provide adequate care and attention to AIDS patients and make their relatives and.the public aware of it.

Hepatitis:
Hepatitis is a liver diseases it is also caused by vims. Inflammation of the liver is its major symptom. When the flow of the bile secreted by the liver is blocked, an increase in the level of bile pigment, bilirubin in blood is noticed. This imparts dark yellow colour to the mucous membrane, white portion of the eyes and the nails. This is the external symptom of diseases.

Mode of transmission:
Disease gets transmitted through contaminated food and water blood components and excreta of the patient.

Biology Chapter 4 Class 10 Kerala Syllabus Question 9.
Complete the table of viral diseases and its modes of transmission

Answer:
a) Through body fluids
b) Chickenpox, Dengue fever
c) Chikungunya, Dengue fever.
d) Rabies

Fungal Diseases

Fungi are of various types. Some fungi are pathogenic. The toxins produced by the fungi cause diseases. Ringworm, Athletes’ foot are fungal diseases.
Given below is the table showing fungal diseases, symptoms and mode of infection

Diseases Caused By Protozoa

Protozoans are unicellular eukaryotes. Malaria is an. example for diseases caused by protozoa.

Sslc Biology Chapter Wise Questions And Answers Question 10.
Prepare a note by analysing illustration and information on malaria.

Answer:
Malaria is caused by the protozoan, plasmodium. Malaria is spread by female Anopheles mosquito. High fever with shivering and profuse sweating are the major symptoms of malaria. Other symptoms include headache, vomiting diarrhoea, anaemia etc. Hoste is man. Symptoms repeat intermittently

Filariasis:
Filariasis is caused by filarial worms that are spread by Culex mosquito. The worms stay in the lymph ducts and obstruct the flow of lymph by blocking the ducts. This causes swelling in the lymph ducts in the legs.

Question 11.
What are the preventive measures to be taken against communicable diseases? What is the significance of observing “Dry Day” in schools and at home? Discuss.
Answer:
Keep the surroundings clean

• Personal hygiene
• Community hygiene
• Eradication of mosquitoes
• Awareness programme – Poster, Rally.

Our carelessness and unclean surroundings are the main reason for the spreading of these types of contagious diseases. Contaminated surroundings promote the multiplication of pathogens and vectors. So it is necessary to avoid situations that lead to communicable diseases. So observing dry day is most effective remedial measure.

Non Pathogenic Diseases

Question 12.
Are diseases caused only by pathogens?
Are they caused by other factors too?
Answer:
No, the diseases are not caused only by pathogens. Many diseases are caused by other factors too. The other factors are

• Lifestyle
• Deficiency of nutrients
• Occupational
• Genetic

Question 13.
Observe the illustration. Give example of diseases for each category.

Answer:

Genetic Diseases

Genes regulate cellular activities. The defects in genes also bring about diseases. Such diseases are called genetic diseases. Haemophilia, sickle cell anaemia etc., are examples of genetic diseases.

Haemophilia:
Haemophilia is the condition that excess blood is lost even through minorwoundsdueto synthesis of protein fails when the genes that control protein synthesis become defective. As haemophilia is a genetic disease a complete cure is not possible. Temporary relief is brought in by injecting the deficient protein identified through clinical diagnosis.

Some social organisations are working for haemophlilia patients who need special care and attention. These organisations volunteerto provide adequate care to haemophilia patients and make their relatives and the public aware of it.

Sickle cell Anaemia:
The defects of genes may also cause deformities in the sequencing of amino acids which are the building blocks of haemoglobin. As a result of this, the structure of haemoglobin changes and this in turn decreases its oxygen carrying capacity.

Question 14.
Why do haemophilia patients loose blood excessively, through minor wounds?
Answer:
Bloods clots with the help of some proteins present in blood plasma. The synthesis of proteins fails when the genes that control protein synthesis become defective. Hence excess blood is lost even through minor wounds.

Question 15.
How does the deformity of red blood cells in sickle cell anaemia patients affect their body?
Answer:
The changes occur in the structure of haemoglobin in red blood cells is cause of these diseases. The blood cells bend like sickle. Decreases the oxygen-carrying capacity of red blood cells. The RBCs in the shape of sickle aggregate and block the flow of blood through the blood vessels.

Cancer:
Cancer is caused by the uncontrolled division of cells and their spread to other tissues. The normal cell gets transformed into cancerous cells when the control system of cell division fails. Various reasons such as environmental factors, smoking, radiations, virus, hereditary facts and alternations in genetic material lead to the transformation of normal cells into cancerous cells.

Question 16.
Early identification of cancer helps the treatment easy. What are the treatments for cancer patients?
Answer:
Surgery, chemotherapy, radiation therapy etc. are used in the treatment of cancer.

Question 17.
Many voluntary organisations are involved in our society to offer better care to cancer patients. What are the importance of such activities?
Answer:
These organisations offer better care to cancer patients. Give love and care to the patients. Give nutritious food, clothes, medicine and proper care. This helps make awareness about people.

Lifestyle Diseases

Lifestyle diseases are caused by unhealthy living style. The changes in food habits, lack of physical exercise, stress, bad habits like consumption of alcohol, drug abuse, smoking etc. lead to various lifestyle diseases

Question 18.
Prepare a table showing lifestyle disease and their causes.
Answer:

Question 19.
Observe the following illustration on some of the health problems associated with smoking

Prepare a poster showing slogans against the habit of smoking.
Answer:

• Cigarette smoking is injurious to health.
• Smoking is a social crime.
• Quit smoking, it kill you

Question 20.
Collect more information on the bad effects of smoking and write it in your science diary.
Answer:
Cigarette smoke contains poisonous substances. They badly harm the respiratory system. Carcinogens present in the smoke cause cancer in respiratory system. Bronchitis and Emphysema are diseases prevalent in smokers. Tobacco smoke injures every part of the respiratory system. It injures the lining of the nose, throat, trachea and lungs. Tobacco smokers, therefore , face a higher risk of lung cancer that non-smokers.

Animal Diseases

Question 21.
Prepare table showing animal diseases and their pathogen.

Plant Diseases

Keeping Diseases Away Let Us Assess

Question 1.
Which among the following is not a bacterial disease?
a) Tuberculosis
b) Nipah
c) Diphtheria
d) Anthrax
Answer:
b) Nipah

Question 2.
“Food safety will be adversely affected with the spread of plant diseases”.
a) Do you agree with this statement? Why?
b) Give two examples of plant diseases?
Answer:
a) Yes, I agree with this statement. We cannot make agriculture profitable by the maximum utilisation of farmland. The main reason for decreasing food production is only the plant diseases.
b) (1) Blight diseases
(2) Bunchy top of banana

Question 3.
Prepare a pamphlet including the major measures to be taken to prevent rat fever.
Answer:
For controlling diseases like rat fever, eliminate the vectors and take preventive medicines as per the directions of experts. Disease affected persons must undergo diagnostic tests to confirm their illness and should take proper medicines. Ensure personal hygiene and environmental hygiene.

Question 4.
What is the importance of vaccination in preventing diphtheria?
Answer:
Antitoxins which act against the toxins produced by Corynebacterium diphtheria are used to protect the uninfected cells. But if the disease becomes severe the patient cannot be recovered through medication. So vaccination is the best preventive method.

Question 5.
What health habits should be adopted to prevent lifestyle diseases?
Answer:

• Avoid the use of food containing higher level of fat and salt.
• Control diabetes and high blood pressure time to time
• Take steps to minimize mental pressure.
• Avoid smoking and alcohol consumption.
• Have regular exercise.

Keeping Diseases Away Extended Activities

Question 1.
Prepare a checklist and collect information on various lifestyle diseases. Find out the lifestyle diseases that are seen commonly. (Hints: Preparing a questionnaire, data collection and analysis)

Question 2.
Prepare and exhibit posters highlighting the fact that social hygiene is as important as personal hygiene.

Keeping Diseases Away More Questions and Answers

Question 1.
Complete the table

Answer:

Question 2.
List the diseases spread by the mosquitoes? Point out the preventive measure.
Answer:
Malaria, Dengue fever, Filariasis, Chikungunya, Yellow fever, Japanese encephalitis, Zika fever etc. are the diseases spread by mosquitoes.
Preventive measures

• Avoid the circumstances leading to spread of mosquitoes
• Observe “Dry Day” once in two weeks.
• Keep our surroundings clean.
• Practice use of measures like mosquito nets.
• Avoid the habit of littering.
• Do not throw garbage’s in the water bodies.

Question 3.
Suppose cholera is being spread in a particular locality. Suggest the precautionary measures to be adopted in the locality?
Answer:
The bacteria causing cholera spread through water or housefly in the dirty atmosphere. Therefore the first and foremost requirement is to keep the surroundings neat and clean Facilitates of clean atmosphere, personal hygiene and pure drinking water should be made available in the cholera affected locality.

Question 4.
Expansion of DOTS is …………..
Answer:
Directly observed treatment short course.

Question 5.
Complete the table given below.

Answer:

Question 6.
During rainy season Athletes’ foot is common’. Give reason?
Answer:
Athlete’s foot is a skin disease caused by certain types of fungi. Pathogens enterthroughthe toes when they come in contact with contaminated water and soil. That is why in rainy season it is very common

Keeping Away Question 7.
Given below is the graph showing the result of a health survey conducted by students in a locality. Analyse the graph and answerthe following questions.

a) Identify the most common disease in that locality?
b) What are the symptoms of that disease?
c) Name the pathogen of each category of the disease.
Answer:
a) Tuberculosis
b) Loss of body weight, fatigue, persistence cough
c) Dengue fever, chikungunya-virus Tuberculosis, cholera – Bacteria

Kerala Syllabus 10th Standard Biology Question 8. Compare Haemophilia and Sickle cell anaemia?
Answer:

10th Standard Biology Question 9.  What does the following picture indicate?

Answer:
Sickle cell Anaemia. Red blood cells bend like a sickle so the oxygen carrying capacity of red blood cells decreases.

Question 10.
Indications about a disease are given in the box. Identify the disease
1. Defects of genes cause deformities in the sequencing of amino acids which are the building blocks of Haemoglobin.
2. Red blood cells bend like a sickle.
3. Decreases the oxygen-carrying capacity of red blood cells.
Answer:
Sickle cell Anaemia.

Question 11.
Smokers and tobacco users are not only subjected to cancer but also many other defects. Evaluate the statement?
Answer:
The statement is correct. There is possibility of diseases like stroke, bronchitis, hypertension etc. apart from cancer in case of frequent users of tobacco products.

Question 12.
Point out some lifestyle habits to prevent heart diseases.
Answer:

• Avoid the use of food containing higher level of fat and salt.
• Control diabetes and high blood pressure time to time
• Take steps to minimize mental pressure.
• Avoid smoking and alcohol consumption.
• Have regular exercise.

Question 13.
“In smokers the ability of blood to receive oxygen is low”.
a) What is the reason for this?
b) Name any two toxic substances present in tobacco? (Model 2015)
Answer:
a) A stable compound, ‘carboxyhaemoglobin’, forms in blood and therefore the transport of oxygen reduces.
b) Nicotine, CO, benzopyrin, Carcinogens (any two)

Question 14.
Analyse the graph showing the diseases that affected the crops in John’s-field and answer the following questions.

a) Identify the most affected crop based on the inference on most prevalent disease.
b) Name the causative agents of the diseases A and C.
c) Which type of insects spread the disease B and D. (Model 2015)
Answer:
a) Paddy
b) Quickwilt- Fungus, Blight disease – Bacteria
c) Aphids

Question 15.
Match the column B and C with column A.

Answer:

Question 16.
Diseases are caused not only by micro organisms. Many of the diseases are caused by bad habits”.
a) Give two suitable examples for the statement given.
b) Substantiate the statement based on the topic habits and diseases. (March 2014)
Answer:
a) Smoking, use of drugs, use of alcohol (any two)
b) Side Effects (three each)

Question 17.
Observe the part of an awareness notice given below:

Precautions:
1. Avoid unprotected sexual relationship
2. Avoid unsterilized injection needles
a) Identify the disease.
b) How unsterilized injection needles transmit this disease? (March 2014)
Answer;
a) AIDS
b) Unsterilized needles used by an AIDS patient contain blood in which HIV present. Transmission through body fluid.

Question 18.
Given below is a graphical representation of the data of individuals who came for treatment on July 2013 in a Government Hospital, Kerala. Analyse the graph and answer the following questions.

a) Which disease is common in this locality?
b) Write a major symptom of this disease.
c) Prepare two posters to be exhibited in an awareness programme against this disease. (March 2014)
Answer:
a) Dengue Fever
b) Blood platelet count decreases internal bleeding and red rashes on the chest or face.
c) Two posters

Question 19.
The blood test of a patient appeared the red blood cells as shown in the figure

a) Identify the affected disease.
b) What are the reasons for this disease?
c) Write a symptom of this disease.
d) How does this disease affect our body? (Model 2013)
Answer:
a) Sickle cell anaemia.
b) Structural deformity in the haemoglobin molecules of the red blood cells due to genetic disorder
c) RBC become sickle-shaped cells.
d) Anaemia due to decreased level of oxygen in the blood and therefore difficulty in doing hard work.

Question 20.
Observe carefully the graph illustrating the data of a survey conducted in certain towns by the Health Department. Analyse the graph and answer to the following questions.

a) Which type of mosquito is dominated in town A?
b) Identify the disease which is likely to be spread in town B. Name the pathogen which causes that disease.
c) Write an important symptom of that disease. (Model 2013)
Answer:
a) Culex mosquitoes
b) Malaria, Protozoa.
c) Severe fever recurring at interval and severe headache.

Question 21.
Name any two bacterial diseases. (March 2012)
Answer:
Any two, For example- Cholera, Typhoid, Rat fever, Leprosy.

Question 22.
Given below are symptoms of a disease.
i) RBC undergo change in shape and transform into sickle-shaped cells.
ii) Oxygen transport to the tissue is reduced.
a) Identify the disease
b) What is the reason for this disease? (March 2012)
Answer:
Sickle cell anaemia, a genetic disorder which deforms the RBC and they become crescent shaped and content of haemoglobin in them is highly reduced.

Keeping Diseases Away Questions and Answers

Question 1.
What do you mean by disease?
Answer:
A disease is a particular abnormal condition, a deviation from the normal functioning of the body systems.

Question 2.
Qn. 2
The causal’Study of disease is called ……………
Answer:
Pathology

Question 3.
Name some pathogens?
Answer:
Virus, bacterim,fungus, protozoa and worms.

Question 4.
Name some communicable diseases?
Answer:
Dengue fever, chikungunya, chickenpox, cholera, Anthrax etc.

Question 5.
Write 2 slogans for the poster in association with mosquitoes day on August 20.
Answer:

• Keep our surroundings clean.
• Observe “Dry Day” once in two weeks

Question 6.
Prepare a flow chart showing the mode of infection of dengue fever.
Answer:

Question 7.
Given belowthe picture of aedes mosquito name two diseases caused by this mosquito.

Answer:
Denque fever, chikungunya

Question 8.
What is the structure of a virus?
Answer:
Virus has the simple structure with a DNA or RNA molecule within a protein coat.

Qn. 9
Name some viral diseases?
Answer:
Dengue fever, chikungunya, Ebola, chickenpox, SAARS, AIDS, Rabies.

Qn. 10
How does vims multiply?
Answer:
Virus multiplies by taking control over the genetic mechanism of host cells. During this process, the cell gets damaged leading to disease.

Qn. 11
“Virus requires a host cell to get multiplied” Give reason?
Answer:
Virus has no cell organelles as seen in normal cells It has the simple structure with a DNA or RNA molecule within a protein coat.

Question 12.
Identify the picture.

Answer:
HIV virus (Human Immuno Deficiency Virus)

Question 13.
Expansion of AIDS?
Answer:
Acquired Immuno Deficiency Syndrome

Question 14.
Expansion of HIV?
Answer:
Human Immuno Deficiency vims

Question 15.
What is AIDS?
Answer:
AIDS (Acquired Immuno Deficiency Syndrome) is a * condition of gradual decrease of immunity by the destruction of lymphocytes by the infection of HIV (Human Immuno Deficiency Virus). HIV enters the body multiplies using the genetic mechanism of lymphocytes.

Question 16.
Read this newspaper cutting
“AIDS-affected children were denied admission in School”
What is your opinion about the decision of the school authorities? Is AIDS a communicable disease?
Answer:
The decision taken by the school authority to refuse admission for AIDS-affected children is totally wrong. This is because AIDS is not a communicable disease. Therefore AIDS vims will not be transferred through touching or sharing food, water, air etc.

Question 17.
Do you think that AIDS will spread through mosquitoes and houseflies?
Answer:
No

Question 18.
The following red ribbon is the international symbol to represent a disease identify the disease?

Question 19.
What are the precautions that can be taken to prevent the spread of virus causing AIDS?
Answer:?
Take precaution before receiving blood. Do not use syringe and needles already used. Have safety in sexual relationship.

Question 20.
Though bacteria are generally helpful, some of them are harmful. How?
Answer:
Bacteria multiply through binary fission immediately after entering the body. The toxins produced by these bacteria damage living cells and thereby bring
about diseases.

Question 21.
Name certain bacterial diseases?
Answer:
Cholera, Typhoid, Tetanus, Tuberculosis, Anthrax, Botulism, Gonorrhoea and Syphilis.

Question 22.
Complete the table of bacterial disease

Answer:
a) Cholera, Typhoid
b) Through wounds
c) Tuberculosis
d) Anthrax
e) Botulism
f) Through sexual contact

Question 23.
AIDS is a viral disease caused through sexual relations. Give examples of two bacterial diseases that are caused by similar manner?
Answer:
Gonorrhoea, Syphilis

Question 24.
Name a bacterial disease spread through air?
Answer:
Tuberculosis

Question 25.
……………… is a bacterial disease that affected the lungs.
Answer:
Tuberculosis.

Question 26.
Identify the bacteria which causes Tuberculosis?
Answer:
Mycobacterium tuberculosis.

Question 27.
………….. treatment is recommended for tuberculosis by World Health Organisation.
Answer:
DOTS

Question 28.
What are the major symptoms of Tuberculosis?
Answer:
Loss of body weight, fatigue, persistent cough are the major symptoms of tuberculosis.

Question 29.
Tuberculosis affects the lungs only’. Do you agree with this statement? Substantiate your answer?
Answer:
Tuberculosis mainly affects the lungs. It also affects kidneys, bones, joints, brain etc by this disease.

Question 30.
…………… is the vaccine used against tuberculosis across the world
Answer:
BCG vaccine

Question 31.
DOTS treatment is given to which category of patients?
Answer:
Patients suffering from Tuberculosis.

Question 32.
Write slogans to give awareness for controlling tuberculosis?
Answer:

• Test your sputum if you have prolonged cough fora couple of weeks.
• Take BCG vaccination immediately after the birth of children.

Question 33.
Name a bacterial disease which can be spread through castles?
Answer:
Anthrax

Question 34.
What is Botulism?
Answer:
Food poisoning caused by the growth of bacteria in improperly sterilized tinned meats and other preserved foods.

Question 35.
Give examples of fungal diseases?
Answer:
Ringworm. Athletes’ foot

Question 36.
How does fungal diseases spread?
Answer:
Fungal diseases spread through contact.

Question 37.
How does fungi cause diseases?
Answer:
The toxins produced by the pathogenic fungi cause diseases.

Question 38.
Malaria is caused by
Answer:
The protozoa plasmodium

Question 39.
Vector of malaria disease?
Answer:
Female Anopheles mosquitoes.

Question 40.
Mention the symptoms of malaria?
Answer:
High fiver with shivering and profuse sweating are the major symptoms of malaria. Other symptoms include headache, vomiting, diarrhoea, anaemia etc.

Question 41.
Filariasis is spread by mosquitoes.
Answer:
Culex mosquitoes

Question 42.
Filariasis is caused by worms.
Answer:
Filarial worms

Question 43.
Observe the figure and answer the following questions.
a) Name the disease?
b) Pathogen?
c) Vector?
d) How to prevent the disease?

Answer:
a) Filariasis
b) Filarial worms
c) Culux mosquitoes
d) Mosquito Control

Question 44.
Find the odd one out
a) Dengue fever, malaria, rabies, filariasis
b) Dengue fever, Rabies, chikungunya, Malaria,
Answer:
a) Rabis – rabies spread through animals, others spread through mosquitoes,
b) Malaria – Malaria is caused by protozoa, others are caused by virus.

Question 45.
Compare Malaria and filariasis with the help of the following indicators.
1. Pathogen
2. Vector
3. Symptoms
Answer:

Question 46.
Give reasons “The legs of Filariasis patients’ swell?
Answer:
Because the filarial worms stay in the lymph ducts and obstruct the flow of lymph by blocking the ducts. This causes swelling in the lymph ducts in the legs.

Question 47.
Give example for a few diseases which are not communicable to person to person?
Answer:
Haemophilia, Sickle cell Anaemia, Cancer, Diabetes, Stroke.

Question 48.
Complete the word relation.
Diabetes: Lifestyle disease
Haemophilia: …………….
Answer:
Genetic disease

Question 49.
Differnciate Anaemia and Sickle cell Anaemia.
Answer:
Anaemia is a condition that develops when your blood lacks enough oxygen content due to the lack of iron content in the red blood cells. On the other hand, sickle cell anaemia is a serious inherited blood disorder where the red blood cells which carry oxygen around the body, develop abnormally. In cause of sickle cell anaemia changes occurs in the structure of haemoglobin in red blood cells. Red blood cell bend like a sickle and hence it is called sickle cell anaemia.

Question 50.
The condition that excess blood is lost even through minor wounds is known as ……………
Answer:
Haemophilia

Question 51.
World Haemophilia Day is observed in ……………….
Answer:
April 17

Question 52.
What do you mean by Haemophilia? What causes it? Is it curable by treatment?
Answer:
Haemophilia is the condition that excess blood is lost even through minor wounds due to synthesis of protein fails when the genes that control protein synthesis become defective. As haemophilia is a genetic disease a complete cure is not possible. Temporary relief is brought in by injecting the deficient protein identified through clinical diagnosis.

Question 53.
Why is sickle cell anaemia called a “Sickle disease”?
Answer:
In case of sickle cell, anaemia changes occur in the structure of haemoglobin in red blood cells. Red blood celsl bend like a sickle and hence it is called sickle cell anaemia.

Question 54.
Smoking causes ………………. cancer
Answer:
Lung cancer

Question 55.
Compare a patient of sickle cell anaemia with a healthy person?
Answer:
Compared to a healthy person, of a person having sickle cell anaemia decreases the oxygen carring capacity.

Question 56.
How does smoking affect the following organs? (Brian, Lungs and Heart)
Answer:

Question 57.
Identify the health issues caused by alcohol consumption?
Answer:
1) Causes kidney disease, ulcers, liver cancer, fatty liver etc.
2) Contributes to high blood pressure and stroke
3) Increases blood sugar levels which makes diabetes worse.

Question 58.
Give examples for diseases caused by unhealthy lifestyle?
Answer:
Diabetes, fatty liver, high blood pressure, stroke, heart attack.

Question 59.
‘India – world capital of Diabetes’ – Explain this news headline?
Answer:
Due to unhealthy food and lifestyle habits, the number of diabetic patients sharply increased in India. Apart from over consumption of food, absents of adequate exercise also contribute to diabetes.

Question 60.
‘Diabetes and high blood pressure are silent killers’ Why?
Answer:
Diabetes and hypertension can damage the kidneys. It increases the risk of blindness and dementia. Untreated hypertension increases the risk of heart disease and stroke. Due to these reasons, diabetes and hypertension are called silent killers.

Question 61.
Name some disease that affects the cattle?
Answer:
Anthrax, Foot and mouth disease, Inflammation of udder.

Question 62.
………………….. is the pathogen of Anthrax
Answer:
Bacillus Anthracis (Bacteria)

Question 63.
Complete the table of diseases that affect the domestic animals.

Answer:
a) Virus – High fever, Blisters in the mouth and on feet, Drop in milk production, weight loss
b) Sudden fever, diarrhoea, mouth sores, nausea and vomiting
c) Inflammation of udder – Bacteria – swelling of udder, drop in milk production.

Question 64.
Complete the word relation?
Cattle : Antrax: Bacteria
Cattle: Foot and mouth diseases: ………………
Answer:
Virus

Question 65.
Prepare a table showing important plant diseases and their pathogen?
Answer:

Question 66.
Complete the word relation
Paddy: Blight: Bacteria
Coconut : Budrot:………..
Answer:
Fungus

Question 67.
………………. is a viral disease which spreads from wild animals to human beings.
Answer:
Ebola

Question 68.
Where and when did Ebola was first idientified?
Answer:
Central Africa in March 2014.

Question 69.
Point out the symptoms of Ebola?
Answer:

• Severe fever
• Muscle pain
• Vomiting
• Diarrhoea
• Internal and external bleeding

Keeping Diseases Away SCERT Questions and Answers

Question 1.
Polluted surroundings and stagnation of water lead to the multiplication of mosquitoes. Mosquitoes carry many diseases to man. One such disease results in the considerable decrease in the number of platelets.
a) Name the disease.
b) Which microbe causes this disease? (Question Pool 2017)
Answer:
a) Dengue
b) Dengue virus

Question 2.
Rearrange columns B & C suiting the pictures in column A. (Question Pool 2017)

Answer:
i- b, R
ii – c, P
iii – a, Q

Question 3.
Choose the statements related to virus from those given below.
a) Multiplies by binary fission.
b) Has a simple structure with a DNA or RNA molecule within a protein coat.
c) Toxins produced by them damage living cells.
d) Multiplies by taking control over the genetic mechanism of host cells. (Question Pool 2017)
Answer:
b, d

Question 4.

Shown above is one of the presentation slides prepared by Pradeep, as part of the International year of Microbes.
a) Which is the microbe mentioned in the slide?
b) Which disease is caused by this microbe?
c) How does this affect the immunity of the body?
Answer:
a)-HIV
b) – AIDS
c) 1. Multiplies using the genetic mechanism of lymphocytes.
2. Considerable decrease in the number of lymphocytes.
3. Disrupts immunity.

Question 5.
Analyse the statements related to the spread of AIDS and classify them suitably.
a) Through mosquitoes & houseflies.
b) Through body fluids.
c) Through extramarital sexual contact.
d) By touch, shaking hands, coughing etc.
e) From HIV infected mother to foetus.
f) When you sit near an HIV infected friend in the school.

Answer:

Question 6.
Complete the illustration of bacterial diseases given below. (Question Pool 2017)

Answer:
A – Tuberculosis
B – Contaminated water/food
C – Tetanus

Question 7.
An interview with the doctor of the Primary Health Centre regarding tuberculosis, organised by the Health Club is given below. What is your explanation for the questions asked by the children?
a) Which bacteria causes this disease.
b) Write two symptoms of this disease.
c) Name the vaccine used to prevent tuberculosis. (Question Pool 2017)
Answer:
a) Mycobacterium tuberculosis
b) Loss of body weight, Fatigue, Persistent cough.
c) BCG

Question 8.
a) What is common between the diseases given in the box?
b) Pick out the odd one. Justify. (Question Pool 2017)
Answer:
a) Diseases spread through air
b) Tuberculosis is a bacterial disease and rest all virus diseases

Question 9.
The result of a survey conducted by the Health Department on mosquito-borne diseases is shown in the graph. Analyse the graph and answer the questions.

a) Which disease affects more number of people?
b) Write symptoms of the disease B.
c) Suggest suitable measures to prevent the spread of the diseases shown in the graph. (Question Pool 2017)
Answer:
a) Filarial worm
b) High fever with shivering, profuse sweating, headache, vomiting, diarrhoea, anaemia etc.
c) Dengue fever, Malaria, Filariasis are the diseases spread by mosquitoes. So avoid the circumstances leading to spread of mosquitoes. Observe ‘Dry Day’ once in two weeks, keep our surroundings clean, practise use of measures like mosquito nets.

Question 10.
Make suitable pairs using the information given in the box.
Diabetes,
Goitre,
Lifestyle,
Haemophilia,
Deficiency of nutrients,
Genetic. (Question Pool 2017)
Answer:

• Diabetes – lifestyle
• Goitre – deficiency disease
• Haemophilia – genetic

Question 11.
Anjanagets wounded on her foot while playing with her friends. Due to continuous bleeding, her parents take her to the hospital. The doctor’s diagnosis after thorough investigation is given below.
“This has happened as the blood is not clotting. This is a genetic disease.”
a) What is Anjana’s disease?
b) How can temporary relief be brought about for the disease? (Question Pool 2017)
Answer:
a) Haemophilia
b) Injecting the deficient protein helps in blood clotting.

Question 12.
Change in the shape of RBC due to genetic disease is shown in the figure.

a) Name the disease shown in the figure.
b) How does the deformity of RBC affect the body?
Answer:
a) Sickle-cell anaemia
b) 1. Decreases the oxygen-carrying capacity of red blood cells.
2. Sickle-shaped RBC aggregate and block the blood flow through blood vessels.

Question 13.
Identify the given symptoms and tabulate them with the name of the disease as headings.
a) The deformity in the sequencing of amino acids of haemoglobin due to the defect of genes.
b) The defect in the production of protein for blood clotting.
c) Excess loss of blood even though a minor wound.
d) The oxygen-carrying capacity of red blood cells decreases. (Question Pool 2017)
Answer:

Question 14.
You are invited to prepare a presentation slide for the Cancer awareness class, conducted by the Health Club. What explanation will you give to the ideas given below?
a) The disease cancer
b) Reasons for cancer
c) Treatment for cancer (Question Pool – 2017)
Answer:
a) Cells undergo uncontrolled division and spread to other tissues.
b) Environmental factors, smoking, radiations, virus, hereditary factors alteration of genetic materials, chemical substances.
c) Chemotherapy, surgery, radiation therapy

Question 15.
An early diagnosis of the disease is crucial in the treatment of cancer. Why? (Question Pool 2017)
Answer:
It is difficult for the patients to recover if the disease becomes severe.

Question 16.
Choose the ones related to lifestyle diseases from those given below.
a) Hereditary factors
b) Lack of exercise
c) Mental stress
d) Environmental factors ‘
e) Change in food habits
f) Alcoholism, smoking
Answer:
b, C, e, f

Question 17.
Arrange the indicators given in column B suitable to column A.

Answer:
A – iii
B – i,
C – ii

Question 18.
Some health issues due to smoking are given below. Name the affected organ. (Question Pool 2017)

Answer:
A – brain
B – lungs
C – any organ

Question 19.
Make a poster to provide awareness about the health issues due to smoking. (Question Pool 2017)
Answer:
Smoking is injurious to health

Question 20.
Classify the diseases given below into animal diseases and plant diseases. (Question Pool 2017)
Anthrax,
Blight disease,
Quick wilt,
Foot and
mouth disease,
Inflammation of udder
Answer:

Question 21.
A study of the Agriculture Department on plant diseases in a panchayath is given below as a graph. Analyse this and answer the questions. (Question Pool 2017)

a) Which is the mostly affected crop?
b) Name the disease that affects pepper.
c) What are the fungal diseases that affected the plants of that area?
Answer:
a) Paddy
b) Quick wilt
c) Bud rot; quick wilt

Question 22.
Analyse the slogan given in the placard and answer the questions

a) What is health?
b) What should be our attitude to patients? (Question Pool 2017)
Answer:
a) The complete physical, mental and social wellbeing of a person.
b) Compassion, mercy, sympathy, empathy, pity, service mindedness and helping mentality etc.

Question 23.
Given below is a doubt raised by Asna when she notices that lungs are mentioned in an advertisement against smoking.
“Does smoking affect only the lungs?”
As a science student, what explanation will you give for this question? (Question Pool 2017)
Answer:

• No
• Affects the Brain, Heart and Blood Vessels.

Question 24.
Nandu: Smoking causes cancer.
Mahesh: Smoking causes lifestyle diseases. Analyse the possibilities of these two statements and write your interpretation. (Question Pool 2017)
Answer:
The statements of both of them are correct. Smoking causes cancer and lifestyle diseases like stroke and hypertension.

Question 25.
Choose the correct statement.
a) Malaria, Filariasis, Cholera etc. are spread by mosquitoes.
b) Anthrax & Rabies are transmitted from animal to man.
c) Tuberculosis, SARS and chickenpox spread through air.
d) Syphilis, Gonorrhoea and Botulism spread (Question Pool 2017)
Answer:
b, c

Question 26.
Analyse the diseases given below and arrange them suitably in the boxes provided,
a. Blight
b. Botulism
c. Ebola
d. Inflammation
e. Quick wilt
f. Foot and of udder mouth disease

Answer:
(a)
(d)
(b)
(e)
(f)
(c)

Question 27.
Classify the diseases given in the box suitably,
a. Anthrax
b.AIDS
c. Bud rot
d. Foot and mouth
e. Athletes foot
f. Tetanus disease
Answer:
Bacteria – (a), (f)
Virus – (b), (d)
Fungus – (c), (e)

Question 28.
Classify the diseases given below based on the mode of transmission. (Question Pool 2017)
1. SAARS,
2. Chikungunya,
3. AIDS,
4. Gonorrhoea,
5. Malaria,
6. Dengue,
7. Syphilis,
8. Chickenpox,
9. Tuberculosis
Answer:

Question 29.

Answer:
i) – (b) – (Q)
(ii) – (c) – (P)
(iii) – (a) – (R)

Question 30.
A few characteristic features of microorganisms are given below. Analyse them and complete the illustration. (Question Pool 2017)

Answer:
A – (iii)
B – (ii)
C – (iv)

Question 31.
Cause of all diseases are microorganisms. All microorganisms are pathogens. Evaluate this statement and justify your answer giving suitable examples. (Question Pool 2017)
Answer:

• Do not agree with this statement.
• Diseases occur without pathogens also, etc. diabetes/stroke/ cancer etc.
• All micro organises are not pathogens. There are useful microorganisms also.

eg: Bacteria seen in the intestine and skin.

Question 32.
Read the statements and answer the questions given below.

a) Identify the disease?
b) Identify the pathogen?
c) Give scientific explanation against the tendency of isolating these persons from the society?
Answer:
a) AIDS
b) HIV (Human Immunodeficiency Virus)
c) This tendency is wrong. HIV spreads only through body fluids, but not by touching, biting, kissing, sneezing, cough, drinking or eating food.

Question 33.
“Unhealthy lifestyle invites diseases”. Justify the statement with examples. (Orukkam 2017)
Answer:
Unhealthy lifestyle may cause diseases like diabetes, fatty liver, hypertension, stroke and heart attack. Smoking may cause lung cancer, bronchitis, emphysema and decrease in the ability of heart.

Question 34.
The extent of the disease affected crops in Rajesh’s farm is represented graphically. Analyse the graph and answer the given questions. (Orukkam – 2017)

a) Identify the most affected crop.
b) Identify the least affected crop.
c) Pair the pathogen and diseases of affected crops,
Answer:
a) Banana
b) Pepper
c) 1. Blight – Bacteria
2. Wilt – Bacteria
3. Bunch top – virus
4. Quick wilt – Fungus

Question 35.
a) What is cancer?
b) How normal cells get transformed into cancerous cells?
c) What are the methods adopted in cancer treatment? (Orukkam 2017)
Answer:
a) Cancer is the condition by which uncontrolled division of cells and their spread to other tissues
b) Environmental factors, smoking, radiations, viruses, hereditary factors and alteration in genetic materials.

Question 36.
The symptoms of a communicable disease are given below.
Loss of body weight, fatigue, persistent cough
a) Name the disease?
b) Identify the pathogen?
c) How this disease is transmitted? (Orukkam 2017)
Answer:
a) Tuberculosis
b) Mycobacterium tuberculosis (Bacteria)
c) Through air

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9th Hindi Notes Kerala Syllabus प्रश्ना 1.
किसी एक त्योहार की ऐतिहासिक या सांस्कृतिक पृष्ठभूमि पर लेख लिखें।

उत्तर:
ओणम : फूलों का त्योहार
ओणम केरल का त्योहार है। केरल के लोग बड़े उत्साह से ओणम’ मनाते हैं। ‘ओणम’ के साथ राजा महाबली और वामन-अवतार की पौराणिक कथा जुड़ी हुई है। राजा महाबली बहुत ही न्यायप्रिय और परम दानवीर था। उसके शासन में प्रजा बहुत सुखी थी। ऐसा विश्वास है कि ‘ओणम’ के दिन महाबली अपनी प्रजा को देखने आते हैं। प्रजा उनका स्वागत-सत्कार करती है। वैसे भी ‘ओणम’ को ‘फूलों का पर्व’ कहा जाता है। क्योंकि ओणम के दस दिन पहले से ही घरों के आँगन में फूलों से रंगोली बनाते हैं।

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General Instructions:

1. The first 15 minutes is the cool off time. You may use the time to read and plan your answers.
2. Answer the questions only after reading the instructions and questions thoroughly.
3. Questions with marks series 1, 2, 3 and 4 are categorized as sections A, B, C and D respectively.
4. Five questions are given in each section. Answer any four from each section.
5. Answer each question by keeping the time.

Time: 1½ Hours
Total Score: 40 Marks

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Kerala State Syllabus 9th Standard Physics Solutions Chapter 4 Gravitation

Gravitation Textual Questions and Answers

Activity – 1

Lifting a small stone to a certain height and then dropping it downwards.

Kerala Syllabus 9th Standard Physics Notes Chapter 4 Question 1.
What do you observe?
Answer:
The stone falls down

Hss Live Guru 9th Physics Kerala Syllabus Chapter 4 Question 2.
What could be the reason for the falling of the stone?
Answer:
Earth’s attraction is the reason

Gravitation Class 9 Kerala Syllabus Chapter 4 Question 3.
What change takes place in the speed of the stone as it is thrown up?
Answer:
Speed decreases

Gravitation Class 9 State Syllabus Chapter 4 Question 4.
What about the speed when it falls down?
Answer:
Speed increases

9th Class Physics 4th Lesson Questions And Answers Question 5.
Did you apply any force on the stone to bring it down?
Answer:
No

9th Class Physics Chapter 4 Kerala Syllabus Question 6.
From where did the stone get the force for the acceleration?
Answer:
The force required for acceleration got from earth’s attraction

Activity – 2

The stone tied to a thread is suspending from a spring balance.

Hsslive Guru Std 9 Physics Kerala Syllabus Chapter 4 Question 7.
What do you observe?
Answer:
Spring is stretched downwards

9th Class Physics Notes Kerala Syllabus Chapter 4 Question 8.
The spring stretched down when the stone was suspended from it. Why?
Answer:
Earth’s attraction is the reason

The earth attracts all objects towards its centre. This force of attraction is the force of gravity.

Conclusion:

• Attraction between two bodies is gravitational force.
• Attraction between bodies and earth is force of gravity.

Kerala Syllabus 9th Standard Physics Notes Pdf Chapter 4 Question 9.
Write down instances where the force of gravity is felt.
Answer:

• Mango falling naturally form a mango tree.
• Stone which is thrown upwards reaches the ground.
• Raindrops falling downwards.
• When we open the bottle filled with water and keeps it upside down water flows out.
• An object in our hands falls down when it is released.

Activity – 3

Weighing a stone of lower mass and another of higher mass by using a spring balance.
Mass of a body is the amount of matter contained in it

Hsslive Guru 9th Physics Kerala Syllabus Chapter 4 Question 10.
In which case was the reading higher?
Answer:
Reading of the spring balance is higher when the stone having greater mass is weighed.

Hss Live Guru Class 9 Physics Kerala Syllabus Chapter 4 Question 11.
Which of the stones experienced greater force of attraction of the earth?
Answer:
Greater force of attraction of the earth is experienced in stone having greater mass.

Physics Chapter 4 Class 9 Notes Kerala Syllabus Question 12.
On the basis of these observations, find out the factor that influences the force of attraction from the earth.
Answer:
The factor is mass

• As the distance between the bodies increases gravitational force decreases.
• Another factor which influences the gravitational force is distance between the objects.

Universal Law of Gravitation:
All bodies in the universe attract each other. The force of attraction between two bodies is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. If two bodies of masses m1 and m2 are separated by a distance d, then

F ∝ m₁, m₂ → (1)
F ∝ 1/d² → (2)
Combining the two, we get

G is the gravitational constant.
The value of G is 6.67 x 10-11 Nm²/kg². The scientist Henry Cavendish determined the value of G for the first time through experiments.

Hss Guru 9 Physics Kerala Syllabus Chapter 4 Question 13.
Complete the table given below, based on Newton’s law of gravitation?

Answer:

Observe the table and find out the answers to the following questions.

Physics Class 9 Chapter 4 Kerala Syllabus Question 14.
Two bodies are at a specific distance so as to attract each other. How many times will the mutual force of attraction be if the mass of one of them is doubled?
Answer:
Mutual force of attraction doubled

Hss Live 9th Physics Kerala Syllabus Chapter 4 Question 15.
What if the mass of both the bodies are doubled?
Answer:
Force of attraction becomes 4 times.

Hsslive Guru Class 9 Physics Kerala Syllabus Chapter 4 Question 16.
What if the distance between the bodies is doubled?
Answer:
When distance is doubled, attractive force reduced as to one fourth (1/4^th).

Kerala Syllabus 9th Standard Physics Notes Chapter 4 Question 17.
What happens when the distance between the bodies is halved?
Answer:
When the distance is halved, force of attraction becomes four times.

9th Physics Notes Kerala Syllabus Chapter 4 Question 18.
Why two children sitting close to each other do not come closer due to mutual force of attraction?
Answer:
The attractive force between two children sitting close to each other are mutual. The force felt by each of them are equal and very short in magnitude. So they do not come closer to each other.

9th Std Physics Notes Kerala Syllabus Chapter 4 Question 19.
A body of mass 50 kg and another body of mass 60 kg are separated by a distance of 2 m. What is the force of attraction between them?
Answer:
m₁ = 50 kg, m₂ = 60 kg
d = 2m, G = 6.67 × 10-11 Nm²/kg²

Force Of Gravity

Force of attraction by a body on earth GMm
F = \(\frac { GMm }{ R² }\)
G – Gravitational constant
M – Mass of earth
m – Mass of body
R – Radius of earth

Class 9 Physics Chapter 4 Notes Kerala Syllabus Question 20.
Is the earth really spherical in shape?
Answer:
No

Question 21.
Is the radius of the earth the same everywhere?
Answer:
No

Question 22.
Where on the surface of the earth is the radius maximum?
Answer:
At the equator

Question 23.
Where is it minimum?
Answer:
At the poles

Question 24.
At which part of the earth must a body be placed so that it will experience the maximum force of attraction? Where the radius is large/where the radius is small?
Answer:
Where the radius is small. Force of attraction is maximum at the poles.

Question 25.
What change occurs in the force of attraction, if a body is being continuously raised from the surface of the earth?
Answer:
If a body is being continuously raised from the surface of the earth, force of attraction decreases.

Question 26.
Suppose if the body is moved from the surface of the earth to the centre. What happens?
Answer:
When it reaches the centre attractive force becomes zero.

Acceleration Due To Gravity

According to II Law of motion.
F = ma
Acceleration due to gravity a = g
i. e, a = g
According to Newton’s law of graviation F = \(\frac { GMm }{ R² }\)
By Newton’s second law of motion, F = ma = mg

Question 27.
Find the factors affecting the value of g?
Answer:

• Mass of the earth
• Radius of the earth

Question 28.
The earth is not a perfect sphere, its radius is not the same everywhere If so, will the value of g be the same everywhere on earth?
Answer:
Value of g be different everywhere on earth

Question 29.
Where will the value of g be the maximum on the earth’s surface?
Answer:
At the poles

Question 30.
Where will it be the minimum?
Answer:
At the equator

Question 31.
What will be the value of g at the centre of the earth?
Answer:
Zero

Consolidation :

• The value of g on the surface of the earth is 9.8 m/s²,
  value of g at pole = 9.78 m/s²
  value of g at equator = 9.83 m/s²
• Value of g at moon is 1/6 of the value of g on the earth.

Question 32.
When a stone of mass 50 kg and another of mass 5 kg fall down simultaneously form the top of a five-storey building, which one will reach the ground first?
Answer:
They reaches the ground at the same time.
Reason: Acceleration due to gravity does not depend on the mass of the body. It will be the same for all
bodies falling to the earth, g = GM/R²

Question 33.
A stone and a sheet of paper are dropped together. Which of the following statements regarding their fall is true?
1. Both of them reach simultaneously
2. The paper reaches first
3. The stone reaches first
Answer:
The paper reaches slowly
Reason: Resistance of air
Feather and Coin Experiment:
The scientist who discovered that freely falling bodies offers air resistance. This was proved by Issac Newton.
Objects like paper fall slowly Galileo was the first person to; argue that this is due to air resistance. Fie wasn’t able to prove it then because at that time: there were no facilities to create a vacuum. Sir Isaac, Newton could prove this later through the ‘feather and coin’ experiment.

Newton placed a feather and a coin in a long transparent tube with closed ends. The tube was: kept vertical at first and then; suddenly turned upside down.

The coin reached the bottom first followed feather a short while later. The experiment was repeated after removing the air inside the tube and it was found that the feather and the coin reached the bottom simultaneously. The conclusion was that the feather took more time to reach the bottom due to air resistance. Thus Galileo’s argument was proved right.

Question 34.
When a stone falls, it attract the earth just as the earth attracts the stone. But it is only the stone that falls, the earth does not rise up. Give reason?
Answer:
Mass of the earth (M) is far greater than that of stone (m). So the acceleration acquired by earth is lesser and that by the stone is greater.

Question 35.
A stone falls down from the top of a wall in 1 s to the ground (g=10 m/s²)
a) What is the speed of the stone just before it touches the ground?
b) Calculate the average speed when the stone is falling down
c) How much is the height of the wall?
Answer:

Question 36.
A ball thrown vertically upward reached a maximum height of 20m
i) What was the velocity of the stone at the instant of throwing up?
ii) How much time did the ball take to reach the height 20 m?
Answer:

Mass and Weight

Mass is measured using common balance. Spring balance is used to measure weight.

• Mass is measured using common balance.
• The quantity of matter present in an object is called mass.
• Spring balance is used to measure weight.
• Weight is the force of attraction exerted by the earth on an object.
  F = mg

Question 37.
Where does a body experience maximum weight on the earth? What is the reason?
Answer:
Maximum weight experiences at the poles. Because value of g is greater at the poles.

Question 38.
Where on the earth does a body experience minimum weight? What is the reason?
Answer:
Minium weight experiences at the equator. Value of g is lesser at the equator.

Question 39.
What is the weight of the body when it is at the center of the earth? Give reasons.
Answer:
At the center, weight is zero. Because value of g is zero

Question 40.
Find out the weight of a body of mass 20 kg. Express the value in newton.
Answer:
F = mg
= 20 × 9.8
= 196 N

Free Fall

When a body is allowed to fall from a height, it falls to the earth due to the force of gravity. This is free fall.

Question 41.
Suppose a spring balance with a body suspended from it is allowed to fall. What will be the reading shown by the balance?
Answer:
Reading will be zero.

Question 46.
During the rotation of a giant wheel, a person experiences loss of weight on the descent. Explain why.
Answer:
Because the giant wheel is in free fall

Question 43.
Why does a freely falling body experience weightlessness? Note it down in your science diary.
Answer:
Due to free fall, the balance cannot exert a reaction force. Also, the force of gravity is utilized to give acceleration for the body.

Question 44.
What is the weight of a body of mass 10 kg?
Answer:
Weight F = mg = 10 × 9.8 = 98 N

Question 45.
If this body is allowed to fall freely, will there be any change in the force experienced by the body?
Answer:
Weight lessens occurs

Question 46.
Drill a hole at the bottom of an open bottle and fill it with water. Water goes out through the hole. Then allow the bottle to fall freely. What do you observe?
Answer:
During free fall, water and the bottle possess some acceleration. So there is no reaction force experiences in water. As a result water does not go out.

Let Us Assess

Question 1.
If the distance between two bodies that attract each other is trebled, how many times will their mutual force of attraction be? (9 time, 3 times, 1/3, 1/9)
Answer:
1/9

Question 2.
A body, the mass and the weight of which were already determined at the Equator, is now placed at the Pole. In this context, choose the correct statement from the following:
a) Mass does not change, weight is maximum
b) Mass does not change, weight is minimum
c) Both mass and weight are maximum
d) Both mass and weight are minimum
Answer:
a) Mass does not change, weight is maximum

Question 3.
Mass of the zeroth is 6 × 10²⁴ kg and that of the Moon is 7.4 × 10²² kg. The distance between Earth and Moon is 3.84 × 10⁵ km. Calculate the force of attraction of Earth of Moon. (G=6.7 × 10^-11 Nm² kg^-2)
Answer:
F = \(\frac { GMm }{ d² }\)

Question 4.
a) What is meant by the terms mass and weight?
b) Are they vector of scalar quantities? Why?
c) The mass of a body is 30 kg. What is its weight on earth? (g = 9.8 m/s²)
d) What is its weight on the moon? (g = 1.62 m/s²) )
Answer:
a) 1. The quantity of matter present in a body is called mass.
2. The force of attraction exerted by earth on a body is referred as weight.
b) Mass is a scalar quantity (No direction)
Weight is a vector quantity (Possess both magnitude and direction)
c) Weight = mg = 30 × 9 = 294 N
d) Weight on the moon = 30 × 1.62 = 48N

Question 5.
If a body of mass 40 kg is kept at a distance of 0.5 m from a body of mass 60 kg, what is the mutual force of attraction between them?
Answer:

Question 6.
Observe the figure and complete the table


Answer:

Gravitation More Questions and Answers

Question 1.
Complete the table

Answer:

Question 2.
How the mass and distance between objects affect gravitational force?
Answer:
Among the two bodies if the mass of one body is doubled gravitational force becomes two times. When the mass of both the bodies are doubled. Gravitational force becomes four times. When the distance increases gravitational force decreases. Gravitational force varies in reciprocal of the square of the distance between the bodies.

Question 3.
Mass and weight of a body is determined at the pole and at the equator
a) Is there any difference in the mass?
b) Is there any change in the weight?
c) Justify the answer
Answer:
a) No change in mass
b) Change will occur
c) Mass is the quantity of matter present in a matter. Value of g is greater at the poles and lesser at the equator. So weight varies. Value of g does not affect the mass

Question 4.
Fill in the blanks.
a) Acceleration due to gravity does not affect the ……………. of the object
b) 1 kg wt = ………….. N
Answer:
a) Mass
b) 9.8

Question 5.
a) What is mean by free fall?
b) Weight of an object in free fall is zero? Why.
c) If a bottle having a hole at the bottom filled with water falling down freely water will not flow out. Why?
Answer:
a) Falling of a body towards earth due to force of gravity is said to be free fall.
b) In free fall the object cannot be able to give reaction force. Also, the gravitational force is utilized to give acceleration to the object.
c) During free fall, the acceleration of water and bottle remains the same. So no reaction force feel in water.

Question 6.
Correct the following.
a) Force of attraction increases when an object is raised from earth’s surface
b) Value of g remains the same on all regions of earth.
Answer:
a) Force of attraction decreases when an object is raised from earth’s surface.
b) Value of g is different on all regions of earth.

Question 7.
a) Calculate the weight of a body in the moon if it weights 150 kg in earth?
b) What will be the weight of a body at the center of earth.
Answer:
a) Weight in the moon = 150 × 1/6 = 25 kg
b) Weight at the center of earth is zero.

Question 8.
a) State Universal Law of gravitation?
b) Represent it mathematically.
c) Mention each letter indicates to what?
d) How mass and distance affect gravitational force?
Answer:
a) Every bodies in the universe attract each other. This attractive force is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.

c) m₁ m₂ – Mass of the bodies
d – Distance between the objects
F – Gravitational force
G – Gravitational constant
d) Mass increases gravitational force increases Distance increases gravitational force decreases.

Question 9.
List the situations in which gravitational force experiences.
Answer:
A mango falls naturally from the mango tree

• Stone reaches the ground when it throws upwards.
• Raindrops falling downwards
• While releasing the hands the object holding in the hand falls to the ground
• Airplane fall to earth when the engine fails.

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Kerala SSLC Physics Model Question Paper 4 Malayalam Medium

General Instructions:

1. The first 15 minutes is the cool off time. You may – use the time to read and plan your answers.
2. Answer the questions only after reading the instructions and questions thoroughly.
3. Questions with marks series 1, 2, 3 and 4 are categorized as sections A, B, C and D respectively.
4. Five questions are given in each section. Answer any four from each section.
5. Answer each question by keeping the time.

Time: 1½ Hours
Total Score: 40 Marks

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Structure of Atom Textual Questions and Answers in Malayalam