This essay question is worth 2 marks, or 20% of your total grade for this lab.

There are a couple of real-life complications to the type of experiment we would conduct above. For each, you should (quickly) research a suitable explanation and write it below.

Real-Life Complication #1:

For a given material with a set work function , there may be an increase in photocurrent (i.e. rate of photoelectrons being ejected) with an increase in frequency of light. This is especially noticeable when the frequency of light is just above but very close to the threshold frequency of the material (i.e. photon energy is very close to the work function). 

By thinking about the structure of electrons within a metal, explain why this is the case; why would (assuming no changes to the number of photons being sent at the cathode) an increase in photon frequency cause an increase in the number of photoelectrons being emitted?

Real-Life Complication #2:

This one is really pedantic, and comes down to the definition of the term 'Intensity'.

Here, let us take 'Intensity' as the amount of power radiated by the light source per area, in Watts per Metre Squared.

With this definition, we get a very curious phenomenon that really only shows up in (some) simulations; if you increase the frequency of the light, you get a DECREASE in total photocurrent. This means that there is a decreased number of electrons being ejected, when the frequency of the light is increased! Why could this be the case? You may wish to think about the number of photons in a beam of light of a given energy.