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Topic Nuclear fission
Asked 6 times across 4 UPSC exams over 43 years (1980–2023), peaking in 1980.
Key insights
- Most tested in CDS — 3 of 6 PYQs
- Most asked in 1980
- Recurs across 6 years (1980–2023)
How it travelled across exams
First appearance in each exam — the same idea, reframed.
CSE 1980 → CDS 2014 → NDA 2021 → GEO 2022
How the concept evolved
Rising — more than half its appearances (4 of 6) are since 2016.
Related concepts
Ideas UPSC tests alongside this one — keep exploring.
Sample questions
You've seen the pattern — here are a few of the actual PYQs.
CDS2023
The hydrogen bomb and the uranium bomb are based, respectively on
- A nuclear fusion and fission ✓
- B fission and thermonuclear fusion
- C geothermal fission and fusion
- D geothermal fusion and fission
✓ Correct answer: (A)
Science & Technology › Energy & Nuclear
GEO2022
Which one of the following statements is true for nuclear fission processes?
- A Light initial nuclides have lesser number of neutrons than protons.
- B Heavy initial nuclides have lesser number of neutrons than protons.
- C All initial nuclides have larger number of neutrons than protons. ✓
- D All initial nuclides have equal number of protons and neutrons.
✓ Correct answer: (C)
Science & Technology › Energy & Nuclear
NDA2021
Nuclear energy is generated by
- A nuclear fission and its expression was proposed by Einstein. ✓
- B nuclear fission and its expression was proposed by Rutherford.
- C nuclear fission and its expression was proposed by Bohr.
- D nuclear fission and its expression was proposed by Heisenberg.
✓ Correct answer: (A)
Science & Technology › Energy & Nuclear
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