JAMB - Physics (2003 - No. 37)
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.
2.17V
1.49V
1.09V
0.34V
Paliwanag
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
∴ Vs = (0.34eV) / e = 0.34V
∴ stopping potential = 0.34V