Concept:The number of photoelectrons emitted per second depends on the rate at which photons strike the metal surface, which is the intensity of the incident radiation.
Explanation:In the photoelectric effect, one photon can eject at most one electron, provided the photon has enough energy to overcome the work function.
The intensity of the incident radiation measures the number of photons arriving per second on the metal surface.
When the intensity increases, more photons strike the surface per second, leading to more emitted electrons per second.
The frequency of the radiation affects the maximum kinetic energy of each emitted electron, not the number of electrons emitted per second.
The work function is the minimum energy required to remove an electron from the metal surface.
Thus, the number of electrons emitted per second is directly proportional to the intensity of the incident radiation.
Answer:A. intensity of the incident radiation