Question

Electromagnetic radiations consisting of photons each of energy greater than the work function of metal falls on the surface of metal. If the intensity of radiation is increased then :

• A. Velocity of ejected electrons increases
• B. The number of photons increases
• C. The ejected electron flux increases
• D. The ejected electron flux decreases

Answer 1

Answer: (B), (C)

The number of photons increases
The ejected electron flux increases

When EM radiation falls on metal surface, the photoelectric effect takes place with following observations,

1. As Intensity (i.e., Amplitude) of EM radiation increases, the number of emitted electrons (i.e. the electric current) increases.

2. Kinetic energy of emitted electrons increases with frequency of EM radiation.

So higher intensity means more number of incident photons and increase in emitted electron flux.

Option B and C are correct.