Name: Photoelectric Effect
Uploaded: 2019-07-19
Duration: 7 min 10 s
Description: What is the phenomenon of photoelectricity, and how can we change photocurrent? Sir Einstein explained the photoelectric effect in 1905. Let's explore his ex...

Question

Explain the effect of potential on photoelectric current.

Accepted Answer

It is found that the photoelectric current increases with an increase in accelerating (positive) potential. At some stage, for a certain positive potential of plate A, all the emitted electrons are collected by the collector plate and the photoelectric current becomes maximum or saturates. This maximum value of the photoelectric current is called saturation current. When the polarity is reversed, the electrons are repelled and only the most energetic electrons are able to reach the collector. The photocurrent is found to decrease rapidly until it drops to zero at a certain sharply defined, critical value of the negative potential $V_{0}$ For a particular frequency of incident radiation, the minimum negative (retarding) potential given to the collector plate for which the photocurrent stops or becomes zero is called the cut-off or stopping potential.

This shows that all the photoelectrons emitted from the metal do not have the same energy. Photoelectric current is zero when the stopping potential is sufficient to repel even the most energetic photoelectrons

Explain the effect of potential on photoelectric current.

Important Questions on Dual Nature of Radiation and Matter

Learn and Prepare for any exam you want !