Question

A charged particle of charge $Q$ and mass $m$ moves with velocity $v$ in a circular path due to transverse magnetic field $B$, then its frequency is

• A. $\frac{QB}{2\pi m}$
• B. $\frac{QvB}{2\pi m}$
• C. $\frac{QmvB}{2\pi }$
• D. $\frac{vB}{2\pi Qm}$

Answer 1

The correct option is A $\frac{QB}{2\pi m}$

Magnetic Field $=B$
Centrifugal Force = $\frac{m{v}^2}{R}$
Magnetic Force $=QvB$
$\frac{m{v}^2}{R}=QvB$
$v=\frac{QBR}{m}$
frequency = $\frac{v}{2\pi R}=\frac{QB}{2\pi m}$