Assertion (A): Deserts can be potential source for generating sustainable energy. Reason (R): Deserts receive more energy from the sun is six hours than mankind consumes in a year. Select The correct answer from the codes given below:

Both statements are true, and the reason actually explains the assertion. Deserts receive intense, uninterrupted solar radiation with clear skies and very little cloud cover. The often-cited fact is that the solar energy falling on deserts in about six hours exceeds what humanity consumes in a whole year. That is why deserts are treated as candidates for large-scale solar power.

Why the other options fail:

• B is wrong because the reason is the correct explanation. It supplies the very basis for the claim that deserts can generate energy.
• C is wrong because the reason is true, as the solar-energy figure above shows.
• D is wrong because the assertion is true. Desert solar parks such as Bhadla in Jodhpur district, Rajasthan, are working examples.

Core concept: solar energy potential and its geographic distribution. For Mains, link it to India's National Solar Mission and the large solar parks in the Thar, and to the trade-offs of land use and ecology in arid zones. The national renewable targets have been revised since 2013, so check current figures before quoting them.

Trap: candidates often reject the reason as 'just a statistic' and pick B. Ask whether the reason gives the logic for the assertion. If it does, it is the correct explanation.