RAS question
Fuel cell technology generates electricity through:
Correct answer: (C) Electrochemical reaction of hydrogen and oxygen.
Fuel cell technology generates electricity through an electrochemical reaction between hydrogen and oxygen, producing electricity, water and heat.
Explanation
Fuel cells are not miniature engines and they do not burn fuel. In a hydrogen fuel cell, hydrogen acts as the fuel and oxygen as the oxidant; their electrochemical reaction generates electricity directly, with water and heat as outputs. ISRO describes hydrogen fuel cells as electric generators working on electrochemical principles, comparable in that respect to batteries, and specifically contrasts them with combustion reactions used in conventional generators. That direct conversion from fuel to electricity explains why fuel cells are treated as highly efficient systems. When pure hydrogen is used, the stated by-product is water, making the technology especially relevant for applications where clean power, heat and water are valuable together.
Why the other options are wrong
- (A) The photovoltaic effect belongs to solar cells, where light is converted into electricity, not to hydrogen-oxygen fuel cell operation.
- (B) Combustion of fuel is the principle of conventional generators or internal combustion engines, whereas ISRO explicitly contrasts fuel cells with combustion-based generation.
- (D) Nuclear fission powers nuclear reactors by splitting atomic nuclei, while a fuel cell works through a hydrogen-oxygen electrochemical reaction.
Concept
This tests the Science and Technology distinction between energy-conversion mechanisms: photovoltaic, combustion, electrochemical and nuclear. It recurs in RAS because clean-energy technologies are often asked through their operating principle rather than only their applications.