Question

The magnetic force acting on charged particle of charge $2\mu C$ in magnetic field of $2T$ acting in $y$ - direction, when the particle velocity is
$\left(2\hat{i}+3\hat{j}\right)\times 10^{6}m{s}^{-1}$ is

• A. 8 N in z-direction
• B. 8 N in y-direction
• C. 4 N in y-direction
• D. 4 N in z-direction

Answer 1

Answer: (A)

$\overrightarrow{F}=q\left(\overrightarrow{V}\times \overrightarrow{B}\right)$
$=2\times 10^{-6}\left[\left(2\hat{i}+3\hat{j}\right)\times 10^6\times 2\hat{j}\right]$
$=2\times 4\hat{k}=8$ N in Z-direction.