A blue laser beam is incident on a metallic surface, causing electrons to be eje

Question

A blue laser beam is incident on a metallic surface, causing electrons to be ejected from the metal. If the frequency of the laser beam is increased while the intensity of the beam is turned down.

a) the rate of ejected electrons will decrease and the maximum kinetic energy will increase

b) the rate of ejected electrons will remain the same but the maximum kinetic energy will increase

c) the rate of ejected electrons will increase and the maximum kinetic energy will increase

d) the rate of ejected electrons will remain the same and the maximum kinetic energy will decrease

I put option C, the rate of ejected electrons will increase and the maximum kinetic energy will increase.

This answer made the most logical sense to me. . One said: If the frequency is increased then the energy incident on the metal also increases. If the frequency is more than threshold frequency more electrons are emitted from the metal surface with more velocity. Then kinetic energy will increase. Could you explain why this thinking is incorrect and what the correct answer is?? Thanks!

Explanation / Answer

If the frequency is increased then the energy incident on the metal also increases.
If the frequency is more than threshold frequency more electrons are emitted from the metal surface with more velocity.
Then kinetic energy will increase

Therefore
the rate of ejected electron wil increase and the maximum kinetic energy will increase.

Answer is (C)

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