171. Which of the following is a moderating material used in nuclear reactor ?
Graphite.
Cadmium.
Zircalloy (an alloy of zirconium and aluminium).
Stainless steel.
✅ The correct answer is option A.
Nuclear Power Engineering MCQs
172. The ratio of atomic radius to its nuclear radius is about
105
108
1012
1015
✅ The correct answer is option A.
173. In nuclear reactions, __________ number is conserved.
mass
atomic
both (a) & (b)
neither (a) nor (b)
✅ The correct answer is option C.
174. A homogeneous reactor is the one, in which the
fissile atoms are evenly distributed throughout the mass of nuclear reactor.
same substance (e.g. heavy water) is used as moderator & coolant.
the fuel and the moderator is mixed to form a homogeneous material.
all (a), (b) and (c).
✅ The correct answer is option C.
175. The half life period of a radioactive substance is best determined by counting the number of alpha particles emitted per second in a Geiger Muller counter from its known quantity. If the half life period of a radioactive substance is one month, then
3/4th of it will disintegrate in two months.
it will completely disintegrate in two months.
it will completely disintegrate in four months.
l/8th of it will remain intact at the end of four months.
✅ The correct answer is option B.
176. Critical energy should be __________ the neutron binding energy of the atom in order to initiate a nuclear fission.
equal to
less than
more than
either more or less
✅ The correct answer is option C.
177. Which is used as a coolant in nuclear reactor due to its high capture cross-section ?
H2
N2
He
CO2
✅ The correct answer is option A.
178. Hydrogen differs from deuterium in __________ properties.
radioactive
physical
chemical
all (a), (b) and (c)
✅ The correct answer is option B.
179. The atomic mass of an element is fractional, because
of uncertainty principle.
it may have isobars.
it contains neutrons.
it may have isotopes.
✅ The correct answer is option D.
180. The function of moderators in nuclear reactor is to
slow down the secondary neutrons.
absorb the secondary neutrons.
control the chain reaction.
none of these.
✅ The correct answer is option A.