RAS question
Green hydrogen is produced by:
Correct answer: (B) Electrolysis of water using renewable energy sources.
Green hydrogen is produced by electrolysis of water using electricity generated from renewable energy sources.
Explanation
Green hydrogen is identified by both its feedstock and its energy source. In the method tested here, water is split into hydrogen and oxygen through electrolysis, and the electricity for that process comes from renewable sources such as solar, wind or hydropower. That is why option B is the best answer: it combines electrolysis with renewable power, producing a clean, emission-free fuel in the sense used by MNRE's green hydrogen overview. The key exam trap is that hydrogen production is not automatically green just because hydrogen is the final fuel; the production route matters. Fossil-fuel routes such as coal gasification or steam methane reforming carry emissions, so they are classified differently.
Why the other options are wrong
- (A) Coal gasification is a fossil-fuel route and produces brown or black hydrogen with high emissions, so it does not match green hydrogen production.
- (C) Steam methane reforming uses natural gas and produces grey hydrogen with carbon dioxide emissions, unlike renewable-powered water electrolysis.
- (D) Nuclear fission is not the renewable-powered electrolysis route asked here; nuclear-powered electrolysis is classified as pink or purple hydrogen, not green hydrogen.
Concept
This tests the environment and energy-transition concept of hydrogen colour classification by production pathway. It recurs in RAS because green hydrogen links renewable energy, decarbonisation and government mission-based climate policy.