Question

A charge particle, having charge q accelerated through a potential difference V enter a perpendicular magnetic field in which it experiences a force F. If V is increased to 5V, the particle will experience a force

• A. F
• B. 5F
• C.
• D.

Answer 1

Answer: (D)

Answer 2

$\frac { 1 } { 2 } m v ^ { 2 } = q V$ $\Rightarrow$ $v = \sqrt { \frac { 2 q V } { m } }$ . Also $F = q v B$

$F \propto \sqrt { V }$ which gives