Question

How to calculate period in magnetic field?

Answer 1

If we have a charged particle in a magnetic field, then the period of its rotation can be determined using Newton's second law

$T=2\pi R/v$

$F=ma\to qvB\sin\alpha=m\frac{v^2\cdot \sin^2\alpha}{R}$ $\to$

$v=\frac{qBR}{m\sin\alpha}$

Finally

$T=\frac{2\pi Rm\sin\alpha}{qBR}=\frac{2\pi m\sin\alpha}{qB}.$ Answer