Q. Which of the following pairs have identical values of $e/m$?
A) A proton and a neutron
B) A proton and deuterium
C) Deuterium and an $\alpha$-particles
D) An electron and $\gamma$-rays
Explanation
(c)
$\frac{\frac{e}{m_{d}}}{\frac{2e}{m_{a - p}}} = \frac{4m_{a - p}}{4m_{d}} = 1$
So, deuterium and an $\alpha$-particles have identical value of $e/m$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.