Question

A charge moving with velocity $v$ in $X-$ direction is subjected to a field of magnetic induction in the negative $X$ direction. As a result the charge will :

• A. remain unaffected
• B. start moving in a circular path in $Y-Z$ plane
• C. retard along $X-$axis
• D. move along a helical path around $X-$ axis

Answer 1

The correct option is A remain unaffected

velocity $V$ is in $X$ direction and magnetic field $B$ is in negative $X$ direction hence angle between the velocity and magnetic field is ${180}^o$.

In given case force on moving charge due to magnetic field is given by,

$F=qVBsin{180}^o=0$

Hence charge remains unaffected.