Question

A charge $q$ is moving with a velocity $\left(v\right)$ parallel to a magnetic field $\left(B\right)$ . Force on the charge due to magnetic field is:

• A. $qvB$
• B. $qB/v$
• C. Zero
• D. $Bv/q$

Answer 1

The correct option is C Zero

Answer is C.

The magnetic force on a moving charge is given as $\overrightarrow{F}=q\overrightarrow{v}\times \overrightarrow{B}$.
The implications of this expression include:
1. The force is perpendicular to both the velocity v of the charge q and the magnetic field B.
2. The magnitude of the force is $F=qvBsin\theta$ where $\theta$ is the angle <180 degrees between the velocity and the magnetic field. This implies that the magnetic force on a stationary charge or a charge moving parallel to the magnetic field is zero.