Q. The ratio of momenta of an electron and proton which are accelerated from rest by a potential difference 50 V is
A) $\frac{m_{e}}{m_{p}}$
B) $\sqrt{\frac{m_{e}}{m_{p}}}$
C) $\frac{m_{p}}{m_{e}}$
D) $\sqrt{\frac{m_{p}}{m_{e}}}$
Explanation
(b) Linear momentum of electron, $p_{e} = \sqrt{{2m}_{e}eV}$
Linear momentum of photon, $p_{p} = \sqrt{2m_{p}eV}$
$\frac{p_{e}}{p_{p}} = \frac{\sqrt{2m_{e}eV}}{\sqrt{2m_{p}eV}}$
$\frac{p_{e}}{p_{p}} = \sqrt{\frac{m_{e}}{m_{p}}}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.