Q. If a cathode ray tube has a potential difference $V$ volt between the cathode and anode, then the speed $v$ of cathode rays is given by
A) $v \propto V^{2}$
B) $v \propto \sqrt{V}$
C) $v \propto V^{- 1}$
D) $v \propto V$
Explanation
(b) $q\ V = \frac{1}{2}mv^{2}$ or $v = \sqrt{2qV/m}$ $ie,\ v \propto \sqrt{V}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.