First slide

Magnetic force

Question

An electron is moving along positive x-axis. To get it moving on an anticlockwise circular path in xy-plane, a magnetic field is applied.

Moderate

A

along positive y-axis
B

along positive z-axis
C

along negative y-axis
D

along negative z-axis

Solution

For the particle to move along anticlock wise path, force should be along $\hat{j}$ . Velocity is along $\hat{i}$ .
Now ${\bar{F}}_{m} = - e (\bar{V} \times \bar{B})$ in terms of unit vectors only.
$\hat{j} = - (\hat{i} \times \hat{?}) \hat{j} = \hat{?} \times \hat{i}$

Clearly, $\hat{?}$ is $\hat{k}$ .

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App