Question

A particle of mass $M$ and charge $Q$ moving with velocity $\overrightarrow{v}$ describes a circular path of radius $R$ when subjected to a uniform transverse magnetic field of induction $\overrightarrow{B}$. The work done by the field when the particle completes one full circle is

• A. $M{V}^2{R}^2$
• B. $0$
• C. $VBQR$
• D. $2\pi VBQR$

Answer 1

The correct option is B $0$

$\overline{F}=q(\overline{V}\times \overline{B})$
Here $\overline{F}$ is perpendicular to the velocity of particle.
So $P=\overline{F}\cdot \overline{V}$
$=0$
So the workdone by the particle $=0$