Answer the following questions.

1. Which of the following is the working principle of a washing machine?

a) centrifugation
b) dialysis
c) reverse osmosis
d) diffusion

2. The tendency of a liquid drop to assume spherical shape is due to

a) surface tension
b) viscosity
c) density
d) vapour pressure

3. Which of the following is a vector quantity?

a) momentum
b) pressure
c) energy
d) work

4. Which of the following statements is true?

a) temperature decreases with increase in altitude
b) temperature increases with the increase in altitude
c) temperature remains the same at any altitude
d) None of these
5. Which of the following is the mode of propagation of heat from the sun to the earth?

a) conduction
b) convection alone
c) radiation alone
d) convection and radiation

6. A nuclear reactor is a device to produce nuclear energy with the help of

a) nuclear fusion
b) uncontrolled chain reaction
c) controlled chain reaction
d) graphite as fuel

7. What is the frequency of the AC Mains in India?

a) 50 cps
b) 60 cps
c) 100 cps
d) 120 cps

8. N-type semiconductors are obtained by adding impurities to pure germanium. These impurities have to be

a) monovalent
b) trivalent
c) tetravalent
d) pentavalent

9. Which of the following is the main source of energy of the sun?

a) nuclear fission
b) nuclear fusion
c) both fission and fusion
d) none of these

10. On which principle does the tape recorder function?

a) electromagnetic induction
b) electrovalency
c) Boyle’s law
d) none of these

11. While functioning what is the temperature level inside a refrigerator?

a) 400 F
b) 450 F
c) 350 F
d) 500 F

12. One litre of water is equivalent to how many kilograms?

a) 1.5 kg
b) 1 kg
c) 1.25 kg
d) .90 kg

13. Which of the following is a renewable source of energy?

a) petroleum
b) kerosene
c) coal
d) tree

14. Which of the following is not a radio active material?

a) Uranium
b) radium
c) plutonium
d) sodium

15. Which of the following is a unit of pressure?

a) Pascal
b) Gauss
c) Ampere
d) Newton

Answers

1. centrifugation
2. surface tension
3. momentum
4. temperature decreases with the increase in altitude
5. radiation alone
6. controlled chain reaction
7. 50 cps
8. pentavalent
9. nuclear fusion
10. electromagnetic induction
11. 400 F
12. .90 kg
13. tree
14. sodium
15. Pascal