Question

an electrically charged particle with mass m, velocity v, and charge q moves in a circle in magnetic field b. what is the formula for the radius of circle r?

Answer 1

Answer:

$r=\frac {mv}{qb}$

Explanation:

In this case,  since the charged particle moves in circular motion,  the centripetal force is equivalent to the magnetic force.

$\frac {mv^{2}}{r}=qvb\\\frac {mv}{r}=qb\\r=\frac {mv}{qb}$