LAWS OF PHOTOELECTRIC EMISSION AND IT'S EXPLANATION IN SIMPLE WAY WITH HELP OF EINSTEIN'S EQUATION

LAWS OF PHOTOELECTRIC EMISSION

1. The photo current is directly proportional  to the intensity of light and is independent of frequency.
2. The kinetic energy of the photo electrons is directly proportional to frequency and is independent of intensity.
3. Photoelectric effect does not happens when the incident frequency is less than a minimum frequency ( threshold frequency )
4. There is no time lag between the incidence of photon and emission of electrons or photoelectric process is an instantaneous. 

Einstein's equation       

 EXPLANATION :

1. According to quantum theory each photon interacts only with  each electron. When the intensity is increases more photons will come and they will interacts with more electrons. This will increase the amount of photo current.
2. According to Einstein's equation  hvo  is constant  then kinetic energy is directly proportional to frequency.
3. We know Einstein's equation. If  v < vo , then kinetic energy becomes negative and it is impossible, in other words photoelectric effect does not happens.
4. According to quantum theory  each photon interact with each electron so different electrons will be interacted with different photons at same instant so there is no time lag between incidence and emission.