Question

28
A particle of mass M and charge Q moving with velocity v describes a circular path of radius R
when subjected to a uniform perpendicular magnetic field of induction B. The work done by the
magnetic field when the particle completes one full circle is
Mv
(B) zero
(A) 2R
R
(C) BQ2R
(D) BOV2R​

Answer 1

Answer:

(b)=0

Explanation:

F'=q(v'xB')

Here F is the perpendicular to velocity of particle.

so,p=f'.v'

=0

therefore the work done by the particle=0

Answer 2

Explanation:

W=F.d.cosø

since d perpenducular to F Cos90=0

hence W=0