Question:
A student performs an experiment on the photoelectric effect, using two materials A and B. A plot of Vstop vs ν is given in the figure.
(i) Which material A or B has a higher work function?
(ii) Given the electric charge of an electron = 1.6 × 10–19 C, find the value of h obtained from the experiment for both A and B. Comment on whether it is consistent with Einstein’s theory
Solution:
(i) The threshold frequency of A is
vOA = 5 × 1014 Hz
The threshold frequency of B is
vOB = 10 × 1014 Hz
Work function is ϕ = hv0
ϕOA/ ϕOB = 5 × 1014/10 × 1014 < 1
ϕOA < ϕOB