Question

A charge $Q$ is moving $\overrightarrow{dI}$ distance in the magnetic field $\vec{B}$. Find the value of work done by $\vec{B}$.

• A. 1
• B. Infinite
• C. Zero
• D. $-1$

Answer 1

Answer: (C)

Since force on a point charge by magnetic field is always perpendicular to
$\vec{v}[\vec{F}=q\vec{V}\times \vec{B}]$

$\therefore$ Work by magnetic force on the point charge is zero.