Question

Assertion : A wheel moving down a perfectly frictionless inclined plane will undergo slipping (not rolling motion)
Reason : For perfect rolling motion, work done against friction is zero.

• A. If both assertion and reason are true and reason is the correct explanation of assertion
• B. If both assertion and reason are true but reason is not the correct explanation of assertion
• C. If assertion is true but reason is false
• D. If both assertion and reason are false

Answer 1

Answer: (B)

Rolling occurs only on account of friction which is a tangential force capable of providing torque when the inclined plane is perfectly smooth, it will simply slip under the effect of its own weight. Once the perfect rolling begins, force of friction becomes zero. Hence, the work done against friction is zero.