(N/A) According to Einstein's photoelectric equation,the intensity of incident radiation is defined as the energy incident per unit area per unit time.
In the particle nature of light,intensity is directly proportional to the number of photons incident on the metal surface per unit time.
Since each photon interacts with a single electron,an increase in the number of incident photons (i.e.,an increase in intensity) leads to an increase in the number of photoelectrons emitted from the surface,provided the frequency of incident light is greater than the threshold frequency $(v > v_{0})$.
Therefore,the photoelectric current,which is the rate of flow of these photoelectrons,is directly proportional to the intensity of the incident radiation.