Question

A charged particle moves through a magnetic field perpendicular to its direction, then

• A. Both momentum and $K.E$ changes.
• B. Momentum and $K.E$ are constant.
• C. $K.E$ changes but momentum is constant.
• D. Momentum changes and $KE$ is constant.

Answer 1

The correct option is D Momentum changes and $KE$ is constant.

The particle will move in a circular path. As we know, work done by the magnetic on a charge particle is zero i.e., its speed remains the same.

Hence, $KE$ remains constant but momentum (direction) changes.

<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> Hence, $\left(D\right)$ is the correct answer.