176. Neutrons have mass approximately equal to that of __________ atoms.
177. Pressure of CO2 gas (which is a coolant) in the Calder-Hall nuclear reactor is __________ kgf/cm2 .
178. The electric power generation cost in nuclear power plant is less than that in a coal based thermal power plant, mainly because the
179. Heavy water used in the nuclear reactors to slow down the speed of neutrons is
180. Thermal neutrons which are used to cause the fission of U-235 have energy __________ eV.
181. Which of the following types of nuclear reactors is most prone to radioactive hazards ?
182. Thermal nuclear reactors using enriched uranium as fuel contains a maximum of __________ percent fissile material i.e. U-235.
183. The atomic weight and atomic number of an element are A and Z respectively. What is the number of neutrons in the atom of that element ?
184. Which of the following is not used as a nuclear fuel cladding material ?
185. The function of moderators in nuclear reactor is to
186. Specific gravity of uranium and plutonium is about
187. If 4 gm of a radioisotope has a half life period of 10 days, the half life of 2 gm of the same istotope will be __________ days.
188. __________ nuclear reactor does not require a heat exchanger to supply steam to power turbine.
189. Radioactive decay is a __________ change.
190. A moderator __________ the neutrons.
191. Thorium can be converted into U-233 in a __________ reactor.
192. Nuclear fuel generally used in reactors is uranium oxide instead of uranium, because the former has higher
193. Nuclear fuel complex, Hyderabad is engaged in the job of
194. Which is a fertile nuclear fuel ?
195. The time required for half of the __________ of a radioactive isotope to decay is called its half life.
196. The ratio of atomic radius to its nuclear radius is about
197. __________ moderator is used in a fast breeder reactor.
198. The velocity of thermal (slow) neutrons triggering nuclear fission reaction (having energy equal to 0.025 eV) is about __________ metres/second.
199. Thermal shield is used in high powered nuclear reactors to
200. 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