Topic Biogas
Asked 9 times across 4 UPSC exams over 45 years (1979–2024), peaking in 2020.
Key insights
- Most tested in CSE — 3 of 9 PYQs
- Most asked in 2020
- Recurs across 8 years (1979–2024)
How it travelled across exams
First appearance in each exam — the same idea, reframed.
CSE 1979 → CDS 2014 → NDA 2020 → CAPF 2024
How the concept evolved
Rising — more than half its appearances (5 of 9) 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.
CAPF2024
Identify the correct option from the following about the proportion of different gases in Biogas?
- A Methane > Carbon dioxide > Nitrogen ✓
- B Methane > Nitrogen > Carbon dioxide
- C Methane > Oxygen > Carbon monoxide
- D Nitrogen > Methane > Carbon dioxide
✓ Correct answer: (A)
Science & Technology › Biology & Health
CDS2022
Which one of the following statements about biogas is not correct ?
- A It is mainly composed of methane gas.
- B It is a non-renewable source of energy. ✓
- C It is formed by the decomposition of cow dung in the absence of oxygen.
- D It burns without smoke and leaves no residue.
✓ Correct answer: (B)
Science & Technology › Energy & Nuclear
NDA2020
Which one of the following statements is NOT correct ?
- A Biomass is a renewable source of energy
- B Gobar gas is produced when cow-dung, crop residues, vegetable waste and sewage are allowed to decompose in the absence of oxygen
- C Biogas generation reduces soil and water pollution
- D Heating capacity of biogas is very low ✓
✓ Correct answer: (D)
Science & Technology › Energy & Nuclear
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