Q. Stopping potential required to reduce the photoelectric current to zero
Solution:
The negative potential at which photoelectric current becomes zero is called stopping potential. If at the stopping potential light of frequency higher than before be made to fall on plate, then photoelectric current is re-established. On increasing the negative potential of other plate, the current again stops. Hence, higher the frequency of the incident light, higher will be the maximum kinetic energy of the emitted photoelectrons or higher will be the stopping potential.
