Q60. Kakrapar Atomic Power Station is located in which Indian state?
[SSC MTS (12 November 2024, Shift 3)]
(A) Rajasthan
(B) Maharashtra
(C) Gujarat
(D) Tamil Nadu
Answer: (C) Gujarat
Explanation: The Kakrapar Atomic Power Station operates near Kakrapar in Gujarat. Its pressurised heavy-water reactors use heavy water for neutron moderation. Rajasthan Atomic Power Station is at Rawatbhata, which is a different location.
Q59. Statement I: India relies heavily on coal despite uranium deposits.
Statement II: Electricity generation requires uranium enriched to at least 60%.
Which is correct?
[UPSC Civil Services Preliminary Examination (2023)]
(A) Both true, II explains I
(B) Both true, II does not explain I
(C) I true, II false
(D) I false, II true
Answer: (C) I true, II false
Explanation: India has uranium resources but historically relies on coal for most electricity. The claim that reactor fuel must contain at least 60% uranium-235 is false; many commercial reactors use much lower enrichment, while Indian PHWRs can use natural uranium.
Q58. The hydrogen bomb and uranium fission bomb operate principally by which processes, respectively?
[UPSC CDS-I General Knowledge (2023)]
(A) Nuclear fusion and nuclear fission
(B) Fission and fusion
(C) Geothermal fission and fusion
(D) Geothermal fusion and fission
Answer: (A) Nuclear fusion and nuclear fission
Explanation: Thermonuclear weapons derive major energy from fusion of light nuclei, generally initiated using fission. A uranium atomic bomb relies primarily on rapid, uncontrolled fission of fissile uranium nuclei. The processes differ in whether nuclei combine or split.
Q57. What Group 18 gas can arise from natural radioactive decay in uranium-bearing soils and rocks?
[SSC CPO Paper-I (5 October 2023, Shift 1)]
(A) Oganesson
(B) Krypton
(C) Radon
(D) Neon
Answer: (C) Radon
Explanation: Radon is a radioactive noble gas formed during decay chains of uranium and radium in rocks and soil. Because it is a gas, it can migrate into buildings. Prolonged exposure to radon decay products increases lung-cancer risk.
Q56. Which radioactive element occupies position 87 in the periodic table and has a short-lived common isotope?
[SSC CHSL Tier-I (10 August 2023, Shift 4)]
(A) Meitnerium
(B) Dubnium
(C) Seaborgium
(D) Francium
Answer: (D) Francium
Explanation: Francium has atomic number 87 and is an alkali metal. Its isotopes are highly unstable; francium-223 has a half-life of roughly 22 minutes. Consequently, francium is exceptionally rare in naturally occurring accessible quantities.
Q55. The radioactive synthetic element seaborgium has which atomic number?
[SSC CGL Tier-I (20 July 2023, Shift 2)]
(A) 110
(B) 106
(C) 102
(D) 113
Answer: (B) 106
Explanation: Seaborgium is designated Sg and has atomic number 106. Named after nuclear chemist Glenn T. Seaborg, it is artificially produced and highly radioactive. An atomic number of 106 means every seaborgium nucleus contains 106 protons.
Q54. How many chemical elements comprise the actinide series?
[SSC MTS 2022 exam cycle (held 20 June 2023, Shift 3)]
(A) 18
(B) 12
(C) 9
(D) 15
Answer: (D) 15
Explanation: The actinide series contains fifteen elements, conventionally actinium through lawrencium. They are f-block elements associated with partially filled 5f orbitals, and all are radioactive. Uranium, thorium and plutonium are especially relevant to nuclear technology.
Q53. A nuclear reactor in a nuclear station is analogous to which part of a coal-fired thermal plant?
[WBCS Mains 2021 exam (held May 2022), Paper IV]
(A) Boiler
(B) Turbine
(C) Electric generator
(D) Exhaust chimney
Answer: (A) Boiler
Explanation: The nuclear reactor is the heat source, analogous to the boiler or furnace in a conventional thermal station. Fission heat is carried away by coolant and ultimately drives a steam cycle connected to an electrical generator.
Q52. What reaction produces the Sun’s radiant energy?
[WBCS Mains 2021 exam (held May 2022), Paper IV]
(A) Nuclear fission
(B) Ordinary disintegration
(C) Photoelectric emission
(D) Nuclear fusion
Answer: (D) Nuclear fusion
Explanation: In the solar core, hydrogen nuclei ultimately fuse into helium through thermonuclear processes. A small loss of mass appears as radiant energy, keeping the Sun luminous. Nuclear fission does not dominate the energy budget of the Sun.
Q51. Cobalt-60 is used in which medical application among the options?
[WBCS Mains 2021 exam (held May 2022), Paper IV]
(A) Electricity generation
(B) Nuclear fission fuel
(C) Fusion fuel
(D) Cancer detection or treatment
Answer: (D) Cancer detection or treatment
Explanation: Cobalt-60 emits penetrating gamma radiation and is used in medical radiotherapy and industrial inspection. Its photons can damage tumour-cell DNA when a carefully planned radiation dose is delivered. It does not function as the usual fuel for a reactor.
