Does the Photoelectric Effect Depend on the Properties of the Incident Light?

Question

INTRO:

Light striking a metal surface causes electrons to be emitted from the metal via the photoelectric effect.

In a particular experiment to study the photoelectric effect, the frequency of the incident light and the temperature of the metal are held constant. Assuming that the light incident on the metal surface causes electrons to be ejected from the metal, the number of electrons emitted from the metal per second decreases.

QUESTION:

In another experiment, the intensity of the incident light and the temperature of the metal are held constant. Assuming that the initial light incident on the metal surface causes electrons to be ejected from the metal, what happens if the frequency of the incident light is increased?

Check all that apply:

a) the work function of the metal increases.

b) the number of electrons emitted from the metal per second decreases.

c) the maximum speed of the emitted electron increases.

d) the stopping potential increases.

Answer 1

This is a bit weird actually.   In the INTRO the rate of emmission decreased even though everything was held constant, this really should only happen if there was less light (at the same frequency) hitting the surface or if the electrons leaving the surface were not being replaced ( so the piece of metal charged up +ve and started attracting electrons back : this may be what you mean by stopping potential increasing)

You are told that the frequency of the light is high enough to emit electrons initially.

In the Question bit, this is another experiment - so what relevance has the INTRO got?   If you assume that the set up is the same as the intro then increasing the frequency should give b) c) and d) but what if it's different?

Have look here and see what you think:

http://hyperphysics.phy-astr.gsu.edu/hba...