Question

A charged particle of a mass m and charge q is released from rest in a uniform electric field E neglecting the effect of gravity, the kinetic energy of the charged particle after t second is

• A. $\frac{eqm}{t}$
• B. $\frac{E^2{q}^2{t}^2}{2m}$
• C. $\frac{2E^2{t}^2}{mg}$
• D. $\frac{E{q}^{2}m}{2t^2}$

Answer 1

The correct option is B $\frac{E^2{q}^2{t}^2}{2m}$

$v=at=\frac{qEt}{m};K.E.=\frac{1}{2}m{v}^2=\frac{q^2{E}^2{t}^2}{2m}$