### 1. Western U.P, Rajasthan, Punjab, Haryana, Tamil Nadu are quite suitable areas for

(a) hydroelectric power plants.

(b) steam power plants.

(c) nuclear power plants.

(d) all of the above.

**Answer: (c) nuclear power plants.**

### 2. One atomic mass unit (amts) is approximately equal to

(a) 1.66 x 10^{-24} kg

(b) 1.66 x 10^{27} kg

(c) 1.6 x 10^{19} kg

(d) 1.6 x 10^{-13} kg

**Answer: (b) 1.66 x 10**

^{27}kg### 3. One atomic mass unit is equivalent to

(a) 931.4 Mev.

(b) 251.2 Mev.

(c) 120.4 Mev.

**Answer: (a) 931.4 Mev.**

### 4. One kilogram of natural uranium gives energy equivalent to about

(a) 100 kg of coal.

(b) 1,000 kg of coal

(c) 5,000 kg of coal.

(d) 10,000 kg of coal.

**Answer: (d) 10,000 kg of coal.**

### 5. Generation of one watt needs about………..fissions per second.

(a) 3.1

(b) 3.1 x 10^{6}

(c) 3.1 x 10^{7}

(d) 3.1 x 10^{10}

**Answer: (d) 3.1 x 10**

^{10}### 6. Particles having the same atomic numbers but different mass numbers are called the

(a) beta particles.

(b) decayed particles.

(c) isotopes.

(d) neutrons.

**Answer: (c) isotopes.**

### 7. In a nuclear reactor thermal energy is obtained from

(a) fission of radioactive materials.

(b) fusion of radioactive materials.

(c) Burning of the fuel rods in oxygen.

**Answer: (a) fission of radioactive materials.**

### 8. Nuclear reactors usually employ

(a) fission.

(b) fusion.

(c) both fission and fusion.

(d) none of the above.

**Answer: (a) fission.**

### 9. In nuclear chain fission reaction each neutron causing fission produces

(a) no new neutron.

(b) less than one new neutron.

(c) one new neutron.

(d) at least one new neutron.

**Answer: (d) at least one new neutron.**

### 10. Which of the following is not a secondary nuclear fuel ?

(a) PU_{239}

(b) U_{233 }

(c) U_{235}

(d) none of above.

**Answer: (c) U**

_{235}### 11. Which of the following are the fertile materials ?

(a) U_{238} and Th_{232 }

(b) U_{238} and Th_{239}

(c) U_{233} and Pu_{239}

(d) U_{238} and Pu_{239 }

**Answer: (a) U**

_{238}and Th_{232 }### 12. Which of the following are the fissile materials ?

(a) U_{238} and Th_{232}

(b) U_{235} , U_{233 }and Pu_{239}

(c) U_{235} and Th_{239}

(d) None of the above.

**Answer: (b) U**

_{235}, U_{233 }and Pu_{239}### 13. In the nuclear fission reactions, isotope of uranium used is

(a) U_{234 }

(b) U_{235}

(c) U_{233}

(d) U_{238 }

**Answer: (c) U**

_{233}### 14. When a nuclear reactor is operating at constant power the multiplication factor

(a) is equal to unity.

(b) is less than unity.

(c) is greater than unity.

(d) may be any of the above.

**Answer: (a) is equal to unity.**

### 15. One fission of U_{235} releases energy of

(a) 335 MeV

(b) 200 MeV

(c) 430 MeV

(d) 525 MeV

**Answer: (b) 200 MeV**

### 16. Which of the following statements are correct ?

- Nuclear fission occurs whenever a uranium nucleus reacts with a neutron.
- Nuclear fission is accompanied by the release of neutrons and gamma rays.
- About 200 MeV of energy is released in the fission of a uranium nucleus.
- Energy from the fission of uranium nucleus is released mainly as the kinetic energy of the neutrons and the energy of gamma radiations.

Select the correct answer using the codes given below. Codes:

(a) 1, 2, 3 and 4.

(b) 2 and 3.

(c) 2, 3 and 4.

(d) 1 and 4.

**Answer: (a) 1, 2, 3 and 4.**

### 17. In what form the initial energy will be released for the 200 MeV per fission by a neutron in a slow thermal nuclear reactor?

(a) Heat energy.

(b) Electromagnetic radiation.

(c) Kinetic energy of particles and electromagnetic radiation.

(d) Kinetic and sound energy.

**Answer: (c) Kinetic energy of particles and electromagnetic radiation.**

### 18. The operation of a nuclear reactor is controlled by controlling the multiplication factor (k), defined as

K = Number of neutrons of any one generation ÷ Number of neutrons of immediately preceding generation

The power level of the reactor can be increased by

(a) raising the value of k above 1 and, keeping it at that raised value.

(b) raising the value of k above 1, but later bringing it back to k = 1.

(c) lowering the value of k below 1 and keeping at that lowered value.

(d) lowering the value of k below 1, but later bringing it back to k = 1.

**Answer: (b) raising the value of k above 1, but later bringing it back to k = 1.**

### 19. Critical mass of the fuel is the amount required to make the multiplication factor

(a) less than unity.

(b) more than unity.

(c) equal to unity.

(d) 0.5

**Answer: (c) equal to unity.**

### 20. The power output of a nuclear power station is proportional to

(a) the rate at which fission reaction occurs

(b) square root of the rate at which fission reaction occurs.

(c) square of the rate at which fission reaction occurs.

(d) none of the above.

**Answer: (a) the rate at which fission reaction occurs**