Question

Assertion : If there is no external torque on a body about its centre of mass, then the velocity of the centre of mass remains constant.
Reason : The linear momentum of an isolated system remains constant.
A. If both, Assertion and Reason are true and the Reason is the correct explanation of the Assertion.
B. If both, Assertion and Reason are true but Reason is not a correct explanation of the Assertion.
C. If Assertion is true but the Reason is false.
D. If both, Assertion and Reason are false.

Answer 1

Correct Answer - D
Here Assertion is false because in the absence of external torque, the angualr momentum of the system torque, the angular momentum of the system of rotation is constant and not the velocity of the centre of mass. Thus velocity will change. Here Reason is true but cannot explain the Assertion.