 ## Model Question: Compulsory Science

Model Question

Subject: Compulsory Science

Full Marks: 75

Time: 2:15 hrs

*Candidates are required to answer in their own words as far as practicable. Credit will be given to originality, not to rote-learning.

Group 'A': Physics

1. a. What are the factors that affect the gravitational force? The value of acceleration due to gravity at polar region of the earth is more, why? The mass of the sun is 2 × 1030kg and that of the Jupiter is 1.9 × 1027kg. If the Jupiter is 7.68 × 108km far from the sun, calculate the gravitational force between them. (1+1+2.5=4.5)

b. What is tidal energy? State any two reasons for giving higher priority to generate hydroelectricity in Nepal. (1+2=3)

2. a. What is relative density? What change in the pressure at the bottom of a drum can be observed when the drum is filled with water is brought from Himalaya to Terai? Give reason. An iron nail sinks in water but floats on mercury, why? (1+1+1.5=3.5)

b. Write any two differences between Archimedes' principle and law of floatation. The volume of a wooden block is 40cm × 30cm × 20cm and its density is 0.8g/cm3. Find out the part of the block that remains inside water when it is kept in water. (Density of water = 1g/cm3) (2+2=4)

3. a. Give reason why cold drink bottles are not completely filled. Study the given table and answer the following questions. (1+1+1+1=4)

 Metals Specific Heat Capacity A 400 J/kgºC B 140 J/kgºC C 460 J/kgºC
1. What is meant by the fact that the specific heat capacity of metal 'C' is 460J/kgºC?
2. If the same amount of heat is given to the same mass of all these metals at the same temperature, which one will gain the highest temperature? Why?
3. Which metal will penetrate into the least depth if each with equal mass is kept on a wax slab after heating up to 100ºC each? Why?

b. A student can read the letters on the textbook clearly but cannot read the letters on the blackboard. Draw a neat and labelled ray diagram by showing his /her defect of vision. Write any one similarity between camera lens and eye lens. On which factor does the power of a lens depend? (1.5+1+0.5=3.5)

4. a. What is a fuse? How are loads connected in domestic wiring? Write any two advantages of that type of connection of loads. (1+0.5+2=3.5)

b. What do you mean by chemical effect of current electricity? Study the given figure and answer the following questions. (1+1.5+1.5=4) 1. Which type of transformer is shown in the given figure? Why?
2. Find out the number of turns of coil in the secondary coil.

Group 'B': Chemistry

5. a. Write any two differences between Mendeleev's periodic table and modern periodic table. What is the 'rate of chemical reaction'? Name the type of the given chemical reaction. (2+1+0.5=3.5)

2AgNO3 + CaCl2 ---> Ca(NO3)2 +2AgCl

b. Draw a neat and labeled figure showing laboratory preparation of ammonia gas. What is isomer? Give the structural formula of isobutene. (2.5+0.5+1=4)

6. a. What is alkali? Which is metal is obtained from argentite. Write the balanced chemical equation of reaction between this metal and dilute nitric acid. Define aqua-regia. (1+0.5+2+1=4.5)

b. Name raw materials required for making water glass. Write down the full form of DDT and PVC. Why are plastics considered as the major cause of chemical pollution? (1+1+1=3)

Group 'C': Biology

7. a. Draw a neat figure of bacteriophase virus and label its any three parts. The number of AIDS patients is increasing day by day in Nepal, why? Write down the function of cerebrospinal fluid. Give an example of negative phototaxis. (1.5+1+1+0.5=4)

b. Which gland is known as emergency gland? Name any two valves found in human heart. What happens if there is shortage of WBCs in blood? The wall of left ventricle is thicker than that of the right ventricle in the human heart. Give reason. (0.5+1+0.5+1.5=3.5)

8. a. Name the type of cell division shown in the given figure and write any two significance of this type of cell division. Write any two differences between pollination and fertilization. (2.5+2=4.5) b. What do you mean by 'alternation of generation'? Name an example of edible mushroom cultivated in Nepal. How is secondary mycelium formed? Write. (1+0.5+1.5=3)

9. a. Why are bacteria called decomposers? Arrange butterfly, snake, eagle, frog and grass in the correct order to make a food chain of a grassland ecosystem. Name the class/division of the organisms shown below with a characteristic of each. (1+1.5+1+1=4.5)

1. Rabbit
2. Sugarcane

b. State Mendel's law of dominance. Draw a chart showing the result obtained in F1 and F2 generations with genotype and phenotype after crossing a long winged drosophila (LL) and a short winged drosophila (ll). (1+2=3)

Group 'D': Geology + Astronomy

10. a. State the hypothesis propounded by George Wofan about the origin of the earth. Why is Mesozoic era called golden era of reptiles? Write any two features of troposphere? (1.5+1.5+1=4)

b. How is supernova formed? Describe in brief. Classify the given heavenly bodies in terms of constellation, planet, comet and galaxy. (1.5+2=3.5)

1. Milky way
2. Saturn
3. Bennet
4. Sagittarius

**Good Luck**