Fundamentals of science, plus space, defence, biotech, and technology in the news.
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Science & Technology for Prelims mixes basic science concepts with applications and current developments — space missions, defence systems, biotechnology, and emerging tech. Much of it is current-affairs driven, resting on a foundation of fundamentals.
Practise the fundamentals and the topical applications together, and revise the areas where terminology or mechanisms trip you up.
S&T questions are often built on the year’s developments — a launch, a defence platform, a health or biotech story — but they usually reward a clear grasp of the underlying concept.
The scope is broad, so consistent, mixed practice and careful review of mistakes are more effective than trying to read every source.
In a nuclear reactor, which one of the following is commonly used as a moderator?
A moderator slows down fast neutrons so that fission can be sustained; heavy water and graphite are common moderators. Cadmium and boron are used in control rods (they absorb neutrons), while uranium is the fuel.
Pick this subject, browse PYQs by year, or start today’s daily drill.
One question at a time, with a timer — the way the real paper feels.
Read the explanation, and every mistake is saved to your notebook for revision.
Largely, yes — but the questions usually test the concept behind the news, so fundamentals still matter.
Practise a mix regularly rather than reading exhaustively, and use the mistake notebook to revise the specific topics you get wrong.
In the PYQ bank — filter by the Science & Technology subject and by year.
Explanations and answers on Likhit Prelims are AI-generated study aids. They may contain errors and can differ from official sources — always verify against authoritative material and the official UPSC answer key.
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