Question

Assertion :A particle of mass $m$ takes uniform horizontal circular motion inside a smooth funnel as shown. Normal reaction in this case is not $mg$$\cos \theta .$ Reason: Acceleration of particle is not along the surface of funnel.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Assertion is incorrect and Reason is correct

Answer 1

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

As particle is moving in horizontal circular motion, horizontal component of normal reaction provides the centripetal force to the particle and vertical component of the normal reaction = mg. In case of particle moving along the surface of the funnel, Normal reaction would just oppose the gravitational pull orthogonal to the surface of the funnel. Hence, assertion and reason both are correct and reason is a correct explanation.