221. A heterogeneous reactor is the one, in which the moderator and the September 7, 2025 by Admin coolant are different materials. coolant are present in different phases (e.g., heavy water and graphite). fuel are present in different phases (e.g. uranium and heavy water). none of these. ✅ The correct answer is option C.
222. Which of the following is artificially produced as it does not occur in nature ? September 7, 2025 by Admin Uranium-235 Uranium-233 Plutonium-239 Both (b) and (c) ✅ The correct answer is option D.
223. First experimental observation of nuclear fission was done by September 7, 2025 by Admin Plane Rutherford Fermi Hahn and Strassman ✅ The correct answer is option C.
224. In β-decay of radioactive material, the ratio of neutron to proton September 7, 2025 by Admin increases. remains same. decreases. is unpredictable; may increase or decrease. ✅ The correct answer is option C.
225. Extraction of uranium from its ore is done by __________ method. September 7, 2025 by Admin chemical pyrometallurgical physical beneficiation electrometallurgical ✅ The correct answer is option A.
226. Nuclear fuel generally used in reactors is uranium oxide instead of uranium, because the former has higher September 7, 2025 by Admin melting point, hence can be subjected to higher temperature. density ; hence core volume for a given power output would be smaller. resistance to effects of irradiation. all (a), (b) and (c). ✅ The correct answer is option D.
227. Which of the following undergoes fission reaction easily ? September 7, 2025 by Admin U-235 U-238 Th-232 none of these ✅ The correct answer is option A.