Question

Write the expression for Lorentz magnetic force on a particle of charge ${}^{\prime }{q}^{\prime }$ moving with velocity $\overrightarrow{v}$ in a magnetic field $\overrightarrow{B}$.Show that no work is done by this force on the charged particle

Answer 1

q=charge of the moving particle

$\overline{B}=$ magnetic field
$\overline{v}=$ Velocity
$\overline{F}=$ magnetic force $=q(\overline{V}\times \overline{B})$
$\overline{F}=q(\overline{V}\times \overline{B})$
Here, $\overline{F}$ is cross product of $\overline{V}$ and $\overline{B}$
so,work done $=W=f,d$
$=Fd\cos {90}^o$
$=0$