Q. The anode voltage of a photocell is kept fixed. The wavelength $\lambda$ of the light falling on the cathode is gradually changed. The plate current 1 of the photocell varies as follows
A) [image:11_image6.emf]
B) [image:11_image7.emf]
C) [image:11_image8.emf]
D) [image:11_image9.emf]
Explanation
(a) On increasing wavelength of light of the photoelectric current decreases and at a certain wavelength (cut off) above which photoelectric current stops
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.