Assertion: The energy of charged particle moving in uniform magnetic field does not change.
Reason: Work done by magnetic field on the charge is zero.

Options

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

Answer

A

Explanation

The force on a charged particle moving in a uniform magnetic field always acts in direction perpendicular to the direction of motion of the charge. As work done by magnetic field on the charge is zero, `[W=FS cos theta]`, so the energy of the charged particle does not change.