Question

In the photoelectric effect, the photoelectric current is independent of
A) Intensity of incident light
B) Potential difference applied between the two electrodes
C) The nature of emitter material
D) Frequency of incident light

Answer 1

Hint: First let us know what Photoelectric Effect means, the photoelectric effect is the emission of electrons when electromagnetic radiation, such as light, hits a material. Electrons emitted in this manner are called photoelectrons.

Complete step by step solution:
Now that we know what the photoelectric effect is, we should discuss the factors affecting the photoelectric effect.
Various studies on the photoelectric effect have presented the following factors which may have a direct impact on the photoelectric effect.

The intensity of Light: If a high-intensity light of frequency equal to or greater than threshold frequency falls on the surface of matter, the photoelectric effect is caused. The emission of electrons does not depend upon the intensity of light unless the frequency of light is greater than the threshold frequency.

Frequency: If a beam of light with a frequency equal to or greater than threshold frequency strikes the surface of matter, the photoelectric effect is produced. If the frequency is less than the threshold frequency then the photoelectric effect cannot be seen. The threshold frequency varies from matter to matter.

Number of Photoelectrons: The increase in the intensity of light increases the number of photoelectrons, provided the frequency is greater than the threshold frequency. In short, the number of photoelectrons increases the photoelectric current.

Kinetic Energy of Photoelectrons: The kinetic energy of photoelectrons increases when the light of high energy falls on the surface of the matter. When the energy of light is equal to threshold energy the electrons are emitted from the surface whereas when energy is greater than threshold energy then photoelectric current is produced. The threshold frequency is not the same for all kinds of matter and it varies from matter to matter.
From the above discussion, we can conclude that the only factor that does not affect the photoelectric current is the frequency of incident light.

Therefore, the correct option is (D).

Note: You might get confused as we have listed the frequency as one of the factors influencing the photoelectric effect and then we said that the photoelectric current is independent of the frequency of incident light. This is true as the frequency only needs to be greater than a threshold or minimum value. Once that minimum value is crossed, frequency change does not affect the photoelectric current.