Question

When monochromatic light is shone on a clean metal surface, electrons are emitted from the surface due to the photoelectric effect. What happens to the emitted electrons when the frequency of the light is increased?

A. Their kinetic energy decreases.
B. Their kinetic energy remains constant.
C. Their kinetic energy increases.
D. Their kinetic energy becomes zero.

Answer 1

When the frequency of the light is increased, the kinetic energy of the emitted electrons increases.

Step-by-step explanation:

When the frequency of the light shone on a clean metal surface is increased, the kinetic energy of the emitted electrons increases.

This is because the energy of a photon of light is directly proportional to its frequency. So, when the frequency of the light is increased, the energy of the photons also increases. Therefore, each emitted electron receives more energy, resulting in an increase in their kinetic energy.

For example, if we consider two beams of monochromatic light with different frequencies, the electrons emitted by the beam with the higher frequency will have higher kinetic energy compared to the electrons emitted by the beam with the lower frequency.