## SLC Model Question Set 5 Science

Full Marks: 75
Pass Marks: 30

Physics

1. a) What is meant by free fall? Does parachute fall freely? Write with reason. Write any two differences between acceleration due to gravity (g) and gravitational constant (G). [1+1.5+1.5=4]

b) Give three alternative sources of energy. What are the two conditions of nuclear fusion reaction found in the sun? Write any two natural phenomena from which geothermal energy can be obtained. [1.5+1+1=3.5]

2. a) Define pressure. Prove the relation of pressure exerted by an object with its surface area and the applied force. By which two properties of liquid is it used in hydraulic brakes? [1+2+1=4]

b) Study the given figure and answer the following questions. [1+1+1.5=3.5]

i) What is the mass of stone in air?
ii) How much upthrust is exerted on the stone?
iii) Which principle is this experiment based on? Write the statement of the principle.

3. a) Define anomalous expansion of water. If water is cooled from 4oC to 0oC, what will be the change on its density? What amount of heat is required to raise the temperature of 20 kg of ice piece from -10oC to 70oC? (Specific heat capacity of ice is 21– J/kgoC and that of water is 4200 J/kgoC.) [1+1+2=4]

b) Write one function of ciliary muscle. What is meant by near point of eye? Draw a ray diagram showing how a compound microscope magnified the image of microorganism. [0.5+1+2=3.5]

4. a) Answer the following questions with the help of the diagrams. [1+1+1.5=3.5]

i) Calculate the total resistance in each circuit.
ii) Find the amount of current flowing in each.
iii) If R1 and R2 are bulbs, in which circuit the bulbs are brighter? Why?

b) What do you mean by 60W written in electric bulb? Miniature circuit breaker (MCB) is used in an electric path, why? Calculate the cost of electricity when 5 electric bulbs each of 100W run for 8 hours a day and two electric heaters each of 1000W run for 2 hours a day. (Cost of 1 unit = Rs. 7) [1+1+2=4]

Chemistry

5. a) What is s-block element? Give an example of it. Why is potassium more reactive than calcium although both of them lie in the same period? Write two drawbacks of Mendeleev’s periodic table. [1+0.5+1.5+1=4]

b) Draw a neat and labelled diagram showing the laboratory preparation of carbondioxide gas. Is the given hydrocarbon saturated or unsaturated? Name the compound formed by the reaction of the above hydrocarbon with saturated hydrocarbon. Also, give its name. [2+0.5+0.5+0.5=3.5]

#### CH3CH2CH=CH2

6. a) Gold is found in nature in pure state but not iron. Why? What is aquaregia? Write its reaction with gold in balanced equation form. [1+1+1.5=3.5]

b) What are the materials used in cement? Why lead crystal glass is called flute glass? Write any two reasons that plastics are useful. Mention two ways to control chemical pollution. [1+1+1+1=4]

Biology

7. a) Define reflex action. name the hormone secreted by male gonads. Mention one important function of this hormone. Answer the following questions based on the diagram:

i) Which process is shown in the diagram?
ii) What is to be done to let the plant grow towards the topmost face of the box? [1+0.5+1+0.5+1=4]

b) How does polio cause paralysis? Give any two preventive measures of AIDS. Give a difference between white blood cell and red blood cell on the basis of their functions. Name the compound which is formed by combination of haemoglobin and oxygen. [1+1+1+0.5=3.5]

8. a) How many chromosomes are there in human sperm and zygote? Why? Which type of cell division is indicated by the given diagram? Where does this type of cell division take place. Give its one importance. [2+0.5+0.5+1=4]

b) What is binary fission? Life cycle of fern plant is divided into how many groups? What are they? Draw a neat and labelled diagram of mushroom. [1+1+1.5=3.5]

9. a) Write the scientific name of maize and classify it. In the given pyramid, biomass of an ecosystem is given, name the ecosystem. What relation between producer and consumer is shown in the given pyramid? Name a bacteria that helps in nitrogen fixation. [0.5+1+0.5+1.5+0.5=4]

b) Why did Mendel select pea plant in his experiment? Give two reasons. Draw a chart to show the result of offspring upto F2 generation when pure round seeded pea plants and wrinkle seeded pea plants are first cross-pollinated and then self-pollinated. Also write the phenotypic ratio of offsprings in F2 generation. [1+2+0.5=3.5]

Geology and Astronomy

10. a) How is it known that there were dinosaurs in the earth in ancient time? In which period were they dominant? What is artificial green house? Give its one use. [1+0.5+1+1=3.5]

b) What happens when hydrogen is finished in the core of the sun? Write two differences between galaxy and constellation. [2+2=4]

## Environment Science

Group ‘A’

Answer any 18 questions from this group. 18×4=72

Physical Aspect

Answer any 7 questions from this sub-group.

1. Write the specific characteristics of green house. How is global climate being changed by human activities? 2+2

2. Describe any two natural green house gases. 2+2

3. Write any two important points and two bad impacts of green house effect. 2+2

4. What is ozone layer? Explain about the atmospheric layer in which ozonosphere lies.  1+3

5. Clarify in what way the ozone is depleted due to action of CFC products. 4

6. Give reasons: 2+2

• Ozone is vital to all forms of life
• Temperature increases with altitude in stratosphere

7. What do you mean by renewable energy resource? Write brief notes about any three renewable energy sources.  1+3

8. Coal is a non-renewable energy source. Why? What are the classes of coal and write their features. 1+3

Chemical Aspect

Attempt any 2 questions from this sub-group.

9. What is meant by radioactive pollution? Explain their causes and effects on human health and environment. 1+3

10. Differentiate between explosive waste and hazardous waste with two examples of each. 4

11. Explain any two safety measures to save life from the hazardous effects of waste. 2+2

Biological Aspect

Attempt any 3 questions from this sub-group.

12. Explain the physiography of Terai and Himalayan regions and list any four endangered animals of those places. 2+2

13. “Domestic animals are important for the farmer.” Explain four examples to justify this statement. 2+2

14. Describe how lack of food and lack of habitat cause disappearance of animals. 4

15. How do National Parks help in wild life conservation? 4

Natural Aspect

Answer any two questions from this sub-group.

16. Classify the wetland areas of Nepal with estimated area coverage percent and an example of each. 4

17. Write about any one man-made wetland area of our country including its importance and need of conservation. 4

18. “Wetland should be properly used.” Give reason. 4

Socio-Economic Aspect

Answer any 2 question from this sub-group.

19. Why is Terai called food basket of Nepal? Give reason. 4

20. Why is Nepal suitable for agriculture and livestock rearing? 4

21. What are the adverse effects of pesticides on agriculture? 4

Health and Sanitation Aspect

Attempt any two questions from this sub-group.

22. How is health related to environment? Give views. 4

23. Write any four effects of radiation. 4

24. Write short notes on: 2+2

• Ventilation
• Extreme temperature

Group ‘B’

Write long answers of any four questions from this group. 4×7=28

25. Write brief note about two control measures of green house gases. Mention four effects of ozone layer depletion and explain three environmental impacts due to lack of energy conservation. 2+2+3

26. Describe four effective ways of hazardous waste management. How do hazardous wastes pollute water? 4+3

27. Do you think the hilly region is also suitable for animals of Himalayan region? Write your opinions. Write short notes on musk dear. 3+4

28. “Wetlands are being destructed.” Explain with four examples. Differentiate between oligotrophic lake and eutrophic lake in three points of each. 4+3

29. Write short notes about four types of irrigation methods. Explain how the organic fertilizers are more advantageous than chemical fertilizers. 4+3

30. Describe four adverse effects on workers working in an unsafe industrial area. How does control in air pollution reduce environmental pollution? 4+3