The sum of masses of two nuclei produced in nuclear fission compared to the mass of original nucleus is_____________________?

A. Less
B. More
C. Same
D. Much more

The velocity of thermal (slow) neutrons triggering nuclear fission reaction (having energy equal to 0.025 eV) is about ______________ metres/second?

A. 1100
B. 2200
C. 3300
D. 4400

Thermal shield is used in high powered nuclear reactors to__________________?

A. Protect the walls of the reactor from radiation damage
B. Absorb the fast neutrons
C. Slow down the secondary neutrons
D. Protect the fuel element from coming in contact with the coolant

Moderating material used in a thermal-reactor should be a ____________________?

A. Good absorber of neutrons
B. Solid substance
C. Poor absorber of neutrons
D. None of these

Which one is the radioactive isotope of hydrogen ?

A. Deuterium
B. Ortho-hydrogen
C. Tritium
D. None of these

Coolant used in a fast breeder reactor is____________________?

A. Molten sodium
B. Heavy water
C. Ordinary water
D. Helium

Which of the following isotopes is not present in natural uranium?

A. U-238
B. U-234
C. U-235
D. U-232

Which of the following is not a good moderating material ?

A. Concrete
B. Boron
C. 18/8 stainless steel
D. All A., B. and C.

Which is a fertile nuclear fuel ?

A. U-233
B. U-235
C. Pu-239
D. Th-232

Heavy water is preferred over ordinary water as a coolant, because it?

A. Acts both as an efficient coolant as well as a moderator
B. Can be heated to a higher temperature without pressurizing
C. Is less prone to radiation damage
D. All A., B. and C.