Q. The mass of an electron is $m$, its charge is $e$ and it is accelerated from rest through a potential difference, $V$. The velocity of electron will be calculated by formula
A) $\sqrt{\frac{V}{m}}$
B) $\sqrt{\frac{eV}{m}}$
C) $\sqrt{\left( \frac{2eV}{m} \right)}$
D) None of these
Explanation
(c)
We know that kinetic energy $= eV$
or $= \frac{1}{2}mv^{2}$
So, $\frac{1}{2}mv^{2} = eV$
$v^{2} = \frac{2eV}{m}$
$\therefore v = \sqrt{\frac{2eV}{m}}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.