UPSC CSE Prelims
Question 95
With reference to 'fuel cells' in which hydrogen-rich fuel and oxygen are used to generate electricity, consider the following statements :
- If pure hydrogen is used as a fuel, the fuel cell emits heat and water as by-products.
- Fuel cells can be used for powering buildings and not for small devices like laptop computers.
- Fuel cells produce electricity in the form of Alternating Current (AC).
Which of the statements given above is/are correct?
View correct answer and explanation
Correct answer: A
Correct Option: A
Explanation: A hydrogen–oxygen fuel cell generates electricity electrochemically, releasing heat and water with pure hydrogen. Fuel cells work at many scales and produce DC, not AC, at the cell output.
Statement/Pair-wise Analysis:
Statement/Item 1: Correct - Combining hydrogen with oxygen in a pure-hydrogen fuel cell produces water and heat.
Statement/Item 2: Incorrect - Fuel cells can power small portable devices as well as buildings and vehicles.
Statement/Item 3: Incorrect - A fuel cell outputs direct current; an inverter is needed if AC is required.
Option-wise Analysis:
A: Correct - includes all and only the correct items.
B: Incorrect - includes incorrect statement/items 2, 3; omits correct statement/item 1.
C: Incorrect - includes incorrect statement/item 3.
D: Incorrect - includes incorrect statement/items 2, 3.