why photoelectric current shows varying graph with frequency

Question

The question is related to the topic dual nature of matter and radiations -photoelectric effect

Answer 1

Since the energy of the incident photon is proportional to its frequency, the kinetic energy of an electron in the photoelectric current will also increase or decrease with frequency.  However, it is not exactly a direct proportion, because the work function of the metal must be subtracted from the energy of the incident photon.  The balance is the kinetic energy of the electron in the photoelectric current.