Question

In the photoelectric effect, the current increases as the intensity of the light increases. Is there an equation for this?

Answer 1

Once the photons have exceeded the energy threshold and are able to eject the electrons, you're correct that the intensity and electron ejection are proportional. I would expect that the proportionality constant is experimentally determined in each case. I've never seen an equation for it.

Answer 2

Hello mate here is your answer.

Basically, the number of photoelectrons emitted is proportional to the number of photons. We assume/know that each photon is associated with removing an electron from the metal. As the number of photons increase(i.e the intensity increases) the number of electrons increases hence the current increases since I=ne.

Hope it helps you.