Prelims 2015 · Science and Technology · Question 95
With reference to 'fuel cells' in which hydrogen-rich fuel and oxygen are used to generate electricity, consider the following statements:<br/>1. If pure hydrogen is used as a fuel, the fuel cell emits heat and water as by-products.<br/>2. Fuel cells can be used for powering buildings and not for small devices like laptop computers.<br/>3. Fuel cells produce electricity in the form of Alternating Current (AC).<br/><br/>Which of the statements given above is/are correct?
Answer
1 only
1. Correct. In a hydrogen fuel cell, hydrogen reacts with oxygen to generate electricity; with pure hydrogen, the main by-products are water and heat.
2. Incorrect. Fuel cells can power both large systems (like buildings) and small devices; portable fuel-cell applications for laptops and similar electronics are feasible.
3. Incorrect. Fuel cells inherently produce Direct Current (DC) electricity, not AC; AC requires an inverter.
Therefore, only statement 1 is correct.