Questions on the Photoelectric Effect

Q4.

The graph shows how the maximum kinetic energy, Ek, of electrons emitted from the surface of metal A, varies with the frequency, f, of the incident electromagnetic radiation.

(a) Explain the meaning of the term threshold frequency.

(2 marks)

(b) Calculate the work function of metal A,

(i) in J,

(ii) in eV.

(3 marks)

(c) Metal A is exchanged for metal B. The work function of metal B is half that of metal A. Add a line to the graph above to show how the maximum kinetic energy of electrons emitted from metal B varies with frequency.

(2 marks)

(d) At a fixed frequency of the incident radiation, the emitted electrons are collected and a current is recorded. State and explain a change that may be made to increase this current. You may be awarded marks for the quality of written communication in your answer.

(3 marks)

(Total 10 marks)