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Assertion: In circular motion, the work done by centripetal force is zero. Reason: In circular motion, centripetal force is perpendicular to the displacement.

1. If both assertion and reason are true and the reason is the correct explanation of the assertion.
2. If both assertion and reason are true but reason is not the correct explanation of the assertion.
3. If assertion is true but reason is false.
4. If the assertion and reason both are false.

Correct answer: If both assertion and reason are true and the reason is the correct explanation of the assertion.

Solution

The centripetal force always acts toward the centre, while instantaneous displacement in circular motion is tangential. Since the force is perpendicular to displacement, the work done is zero, so both statements are true and the reason explains the assertion.

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