Question

A negatively charged particle is falling freely under gravity enters a region having uniform horizontal magnetic field pointing towards South. The particle will be deflected towards -

• A. East
• B. West
• C. North
• D. South

Answer 1

The correct option is A East


As per the question, negatively charged particle is falling under gravity and the direction of magnetic field $\overrightarrow{B}$ is towards South.

From the given information we can take the direction of $\overrightarrow{v}$ and $\overrightarrow{B}$ as $\hat{v}=-\hat{j}$ and $\hat{B}=\hat{k}$ respectively.

Now, the direction of magnetic force on a charged particle is,

$\widehat{F_m}=\hat{v}\times \hat{B}=-\hat{j}\times \hat{k}=-\hat{i}($West$)$

As the particle is negatively charged, so the direction of $\overrightarrow{F}$ will be towards East.

<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> Hence, it will deflect towards East.