Assertion: If a charged particle is moving on a circular path in a perpendicular magnetic field, the momentum of the particle is not changing.
Reason: Velocity of the particle in not changing in the magnetic field.

Options

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 the correct explanation of the assertion
C. If assertion is true but reason is false.
D. If the assertion and reason both are false.

Answer

D

Explanation

When a charged particle is moving in a circular path in a magnetic field, the magnitude of velocity does not change but direction of velocity changes every moment. Hence velocity is changes, so momentum `(mvecv)`also changes.