The maximum kinetic energy of the photoelectron emitted from a metal surface is 0.34eV. If the work function of the metal surface is 1.83eV; find the stopping potential?

A. 2.17V
B. 1.49V
C. 1.09V
D. 0.34V

Correct Answer:

Option D – 0.34V

Explanation

The stopping potential is the potential required to stop the most energetic photo-emitted electron. From the relation e Vs = K.E,(max) where e is the electron charge, and Vs is the stopping potential => e x Vs = 0.34eV
∴ Vs = (0.34eV) / e = 0.34V
∴ stopping potential = 0.34V