UPSC Prelims 2025 Q41: Science & Technology – Energy & Environment
- (a) Only one
- (b) Only two
- (c) All the three
- (d) None
Answer: (c) All the three
Explanation
Vehicle Types - Energy Classification:
| Vehicle Type | Energy Source | Uses Combustion Engine? | Alternative Powertrain? |
|---|---|---|---|
| Full Battery Electric (BEV) | Lithium-ion battery → electric motor | NO | YES |
| Hydrogen Fuel Cell (FCEV) | H₂ + O₂ electrochemical reaction → electricity → motor | NO | YES |
| Fuel Cell-Electric Hybrid | Hydrogen fuel cell + battery pack, no combustion engine | NO | YES |
Alternative Powertrain = any propulsion system that is NOT a conventional Internal Combustion Engine (ICE) burning petrol or diesel.
All three qualify — none use a combustion engine.
BEV uses stored electrical energy.
FCEV generates electricity from hydrogen through a fuel cell (chemical reaction, not combustion).
Fuel cell-electric hybrid combines both — still no ICE.
Answer: (c) All the three.
Why each option is right or wrong
- (a) Incorrect. All three qualify as alternative powertrains, not just one.
- (b) Incorrect. Fuel cell-electric hybrids also qualify — they use hydrogen fuel cells as primary energy with no combustion engine at all.
- (c) CORRECT. BEV, FCEV, and fuel cell-electric hybrid are all alternative powertrain vehicles — none rely on a conventional internal combustion engine burning fossil fuels.
- (d) Incorrect. All three are well-established alternative powertrain categories recognised by IEA and global automotive standards.
Key point
Alternative powertrain = NOT conventional ICE. BEV + FCEV + Fuel cell-electric hybrid = all three qualify. Zero fossil fuel combustion in any of them.
Remember
BEV + FCEV + fuel cell-electric hybrid = all three are alternative powertrains. None have a combustion engine.
Common mistakes
- Thinking hybrid always means conventional petrol+electric hybrid. Fuel cell-electric hybrids use hydrogen+battery — no combustion engine at all.
- Confusing hydrogen fuel cell vehicles with hydrogen combustion engines. FCEVs generate electricity from H₂+O₂ reaction — no combustion occurs.
- Not knowing the simple definition: alternative powertrain = any non-ICE propulsion system.
Exam tip
EV types: BEV = battery only (no engine). FCEV = hydrogen fuel cell (no engine). PHEV = plug-in hybrid (engine + battery, has plug). HEV = conventional hybrid (engine + battery, no plug). Only PHEV and HEV involve combustion engines.
Sources
- IEA — Global EV Outlook 2023 (Alternative Powertrain Classification)
- Ministry of Heavy Industries — FAME India Scheme (EV Categories)
- NCERT Class XII — Chemistry (Electrochemistry and Fuel Cells)