Q. In a $PN$ junction photo cell, the value of photo-electromotive force produced by monochromatic light is proportional to
A) The voltage applied at the $PN$ junction
B) The barrier voltage at the $PN$ junction
C) The intensity of the light falling on the cell
D) The frequency of the light falling on the cell
Explanation
(c) When a light (wavelength sufficient to break the covalent bond) falls on the junction, new hole electron pairs are created. No. of produced electron hole pairs depend upon no. of photons. So photo $e.m.f.$ or current is proportional to intensity of light
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.