Sources of energy Worksheet-3

Sources of energy Worksheet-3

 

  1. The fraction of the total solar energy received by the Earth is :

A. one hundredth                         B. one thousandth

C. one billionth                             D. One millionth.

 

  1. The approximate temperature of the surface of the Sun is :

A. 3000°C                                      B. 30,000°C

C. 6000°C                                      D. 10,000°C

 

  1. Which of the following is a primary fuel?

A. Kerosene       B. Wood             C. Petrol             D. Diesel

 

  1. Which of the following is a secondary fuel?

A. Wood             B. Coal               C. Diesel            D. Natural gas.

 

  1. The device which harnesses solar energy directly is :

A. Coal gas plant                          B. Natural gas plant

C. Solar cell                                   D. Biogas plant.

 

  1. U-235 content in natural uranium is :

A. 0.006%         B. 0.714%          C. 99.2%            D. 100%

 

  1. Energy released in the fission of one nucleus of U-235 is about:

A. 1 MeV            B. 20 MeV         C. 200 MeV      D. 2000 MeV

 

  1. Energy released in the fission of 1 kg of U-235 is equivalent to energy obtained from burning of coal weighing :

A. 25 ton            B. 250 ton          C. 2500 ton       D. 25000 ton

 

  1. One MeV of energy is equivalent to :

A. 1.6 × 10–13 J                              B. 1.6 × 10–19 J

C. 1.6 × 1013 J                                D. 1.6 × 1019 J

 

  1. One unified atomic mass unit (u) is equivalent to :

A. 1 eV                B. 1 MeV            C. 931 MeV       D. 931eV

 

  1. Common moderator used in nuclear reactor is :

A. graphite        B. cadmium      C. boron             D. Uranium.

 

  1. Disposal of nuclear waste is a challenge because it is :

A. too large        B. too heavy      C. radioactive   D. foul smelling

 

  1. Uncontrolled nuclear chain reaction is the basis of:

A. nuclear reactor                        B. atom bomb

C. hydrogen bomb                       D. None of these.

 

Answer Key:

  1. C
  2. C
  3. B
  4. C
  5. C
  6. B
  7. C
  8. C
  9. A

Explanation: 1 MeV = 106 eV = 108 (1.6 × 10–19 J) = 1.6 × 10–13 J

  1. C

Explanation: 1 u = 931 MeV.

  1. A
  2. C

Explanation: Waste from nuclear fission reactions is  radioactive. It emits nuclear radiations which are harmful.

  1. B