Q. A deutron of kinetic energy 50 keV is describing a circular orbit of radius 0.5 m in a plane perpendicular to magnetic field $\overrightarrow{B}$. The kinetic energy of the proton that describes a circular orbit of radius 0.5 m in the same plane with the same $\overrightarrow{B}$ is

A) 200 keV
B) 100 keV
C) 50 keV
D) 25 keV
Explanation

(b) $r = \ \sqrt{\frac{2m_{1}{E_{k}}_{1}}{Bq_{1}}}$ =$\sqrt{\frac{2m_{2}{E_{k}}_{2}}{Bq_{2}}}$
Or ${E_{k}}_{2} = \frac{m_{1}}{m_{2}}\frac{q_{2}}{q_{1}}\ {E_{k}}_{1}$
$= \frac{2m}{m} \times \frac{q}{q} \times 50$ keV = 100 keV

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.