Question

What happens to the kinetic energy of the emitted electrons when the light is incident on a metal surface?

• A. It varies with the frequency of light
• B. It varies with the light intensity
• C. It varies with the speed of light
• D. It varies irregularly

Hint:

In the photoelectric effect, the kinetic energy of emitted electrons is determined by the frequency of the incident light, not by its intensity.

Answer 1

The Correct Option is A

Step 1: Photoelectric effect.
According to Einstein's photoelectric equation, the kinetic energy of emitted electrons depends on the frequency of the incident light: \[ K.E.
= h\nu - \phi \] where \( h \) is Planck's constant, \( \nu \) is the frequency of the incident light, and \( \phi \) is the work function of the metal.
Step 2: Identify the correct option.
The kinetic energy of the emitted electrons increases with the frequency of light, and not with the light intensity.