MP Board · Class 12 · Physics · Moving Charges and MagnetismWhat is the radius of the circular path of a charged particle in a perpendicular magnetic field?

When a charged particle of mass $m$ and charge $q$ enters a uniform magnetic field $B$ perpendicularly with velocity $v$, it follows a circular path. The magnetic force provides the necessary centripetal force. Equating $qvB = \frac{mv^2}{r}$, the radius $r$ of the circular path is derived as $r = \frac{mv}{qB} = \frac{p}{qB}$, where $p$ is the linear momentum of the charged particle.