Q. An electron of mass $m$ and charge $e$ is accelerated from rest through a potential difference $V$ in vacuum. The final speed of the electron will be
A) $V\sqrt{e/m}$
B) $\sqrt{eV/m}$
C) $\sqrt{2eV/m}$
D) $2eV/m$
Explanation
(c) Kinetic energy $K = \frac{1}{2}mv^{2} = eV \Rightarrow v = \sqrt{\frac{2eV}{m}}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.