Question

A charged particle of mass ' $m$ ' and charge ' $q$ ' is released from rest in an uniform electric field $\vec{ E }$. Neglecting the effect of gravity, the kinetic energy of the charged particle after ' $t$ ' seconds is

• A. $\frac{\text { Eqm }}{t}$
• B. $\frac{ E ^{2} q ^{2} t ^{2}}{2 m }$
• C. $\frac{2 E ^{2} t ^{2}}{ mq }$
• D. $\frac{ E ^{2} q ^{2} m }{2 t ^{2}}$

Answer 1

Answer: (B)

$K . E =\frac{1}{2} mv ^{2}$
$=\frac{1}{2} m \left(0+\frac{ Eq }{ m } t \right)^{2}$