Question

A $e^{-}$ when accelerated by $V$ volts experience a force $F$ when it enters a uniform magnetic field. What will the force experienced when it is accelerated by $2V$ volts.

• A. $F$
• B. $2F$
• C. $\frac{F}{2}$
• D. $\sqrt{2}F$

Answer 1

The correct option is D $\sqrt{2}F$

$\frac{1}{2}m{v}^2=qV$ so velocity $v\alpha \sqrt{V}$ and forse $F=qvB$
So $F\alpha \sqrt{V}$
So now force $F=\sqrt{2}F$