Question

What is the direction of magnetic force on the negatively charged particle $q$ which enters a magnetic field, as shown in the figure?

• A. Left
• B. Right
• C. Upward
• D. Downward

Answer 1

The correct option is A Left

Given:


From the given information, we can take the directions of $\overrightarrow{v}$ and $\overrightarrow{B}$ along $Y-$ and $Z-$ directions, respectively.

So, $\hat{v}=\hat{j}$ and $\hat{B}=\hat{k}$

Where, $\hat{j}$ and $\hat{k}$ are unit vectors along $Y-$ and $Z-$ directions, respectively.


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

$\widehat{F_m}=\hat{v}\times \hat{B}=\hat{j}\times \hat{k}=\hat{i}$

As the charge $q$ is negative, so the direction of $\overrightarrow{F}$ will be towards left.

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

<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}-->