A charged particle of mass m and charge q is projected with velocity $\overrightarrow{v}$  into a uniform magnetic field $\overrightarrow{B}$ . The force experienced by the particle is:

Force on a change q moving in a magnetic field is known as Lorentz force given as

$F=qvB\sin \theta$     …(i)

Where $\theta$  is the angle between $\overrightarrow{v}$  and $\overrightarrow{B}$ . Velocity we write eq. (i) as

$\overrightarrow{F}=q\left(\overrightarrow{v}\times \overrightarrow{B}\right)$