The half life period of a radioactive element is 100 days. After 400 days, one gm of the element will be reduced to ______________ gm?

A. 1/4
B. 1/8
C. 1/2
D. 1/16

Artificially produced radioactive isotopes are used for____________________?

A. Power generation
B. Treatment of certain diseases
C. Initiating nuclear fission and fusion
D. All A., B. and C.

Which of the following types of nuclear reactors is most prone to radioactive hazards ?

A. Pressurised water reactor
B. Gas cooled reactor
C. Molten sodium cooled reactor
D. Boiling water reactor

U-235 content in enriched uranium, that is normally used in power reactors (e.g., at Tarapur atomic power plant), is about _____________ percent?

A. 85
B. 50
C. 3
D. 97

Extraction of uranium from its ore is done by ______________ method?

A. Chemical
B. Pyrometallurgical
C. Physical beneficiation
D. Electrometallurgical

The molecular weight of heavy water is_________________?

A. 10
B. 18
C. 20
D. 36

Fast breeder nuclear reactors using enriched uranium as fuel may contain upto a maximum of ____________ percent of U-235 (i.e. fissile material)?

A. 15
B. 45
C. 65
D. 85

Critical energy should be _______________ the neutron binding energy of the atom in order to initiate a nuclear fission?

A. Equal to
B. Less than
C. More than
D. Either more or less

A nuclear reactor can’t be used for_________________?

A. The production of radioisotopes
B. Supplying intense fields or beams of neutron for scientific experiments
C. Marine ship propulsion
D. None of these

Uranium is recovered from its ore (pitchblende) by________________?

A. Froth floatation technique
B. Leaching with sulphuric acid
C. Smelting in a furnace
D. Dissolving in water