Q. Photons with energy 5 eV are incident on a cathode C in a photoelectric cell. The maximum energy of emitted photoelectrons is 2 eV. When photons of energy 6 eV are incident on C, no photoelectrons will reach the anode A, if the stopping potential of A relative to C is:-
A) +3 V
B) +4 V
C) -1 V
D) -3 V
Explanation
[Solution] Work function = 3 eV; with 6 eV photons KE max = 3 eV, so the anode must be at -3 V relative to C. Answer (4).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.