Q. 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 ?
A) four times
B) one-fourth
C) zero
D) doubled
Explanation
[Solution] Halving the frequency gives $0.75\nu_0$, below threshold, so no photoemission: current is zero. The source key gives (4), which is incorrect. Answer (3).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.