Explain the effect of potential on photoelectric current in the experiment of the photoelectric effect.

(N/A) In the experiment of the photoelectric effect,the collector plate $A$ is kept at a positive potential relative to the emitter.
When the magnitude of the positive potential is increased,the photoelectric current also increases because more electrons are attracted to the collector.
For a particular positive voltage on plate $A$,all emitted electrons reach the collector,and the current reaches its maximum value.
If the collector voltage is increased further beyond this point,the photoelectric current does not increase. This maximum value of current is called the saturation current.
When the collector voltage is sequentially decreased and made negative,a repulsive force acts on the electrons.
As the collector voltage becomes more negative,the repulsive force increases,allowing only the most energetic electrons to reach the collector. Consequently,the collector current decreases rapidly.
The specific value of negative potential at which the photoelectric current becomes zero is known as the cut-off voltage or stopping potential,denoted by $V_{0}$.
Since the energy of electrons emitted from the metal surface varies,the stopping potential provides a measure of the maximum kinetic energy of the photoelectrons.
When the photoelectric current becomes zero,the maximum kinetic energy $(K_{\max})$ of the photoelectrons is equal to the work done by the retarding potential.
Therefore,$K_{\max} = e V_{0}$.