Question

A strong magnetic field is applied on a stationary electron. Then the electron:

• A. moves in the direction of the field
• B. remains stationary
• C. starts spinning
• D. moves opposite to the direction of the field

Answer 1

Answer: (B)

remains stationary

As $\overrightarrow{F}=\overrightarrow{q}(\overrightarrow{v}\times \overrightarrow{B})$
As the electron is stationary, $\therefore velocity\overrightarrow{v}=0$.
$\therefore \overrightarrow{F}=0$. So, electron will remain stationary.