Q 12-11-013NEETNEET 2020Top questionEasy
Light of frequency $1.5$ times the threshold frequency is incident on a photosensitive material. What will be the photoelectric current if the frequency is halved and intensity is doubled ?
Answer: (D) zero
Concept. Below the threshold frequency there is no emission at any intensity.
Step 1. New frequency. $\dfrac{1.5\nu_0}{2} = 0.75\nu_0 < \nu_0$.
Step 2. Current. Zero.
Answer. Zero (Option D).
Solution by Sreeraj P, M.Sc Physics