(a) Define the terms (i) work function and (ii) threshold frequency for a metal…
PHYSICS · Subjective · A Level · Physics · Particles and radiation · Particles and radiation
Problem
(a) Define the terms (i) work function and (ii) threshold frequency for a metal surface.
(b) Show that for any metal the threshold wavelength λ0 is inversely proportional to its work function ϕ.
(c) A set of experimental readings of stopping potential V0 versus frequency ν for a clean metallic surface produces a straight-line graph that meets the frequency axis at 5.0×1014Hz. Explain qualitatively how this intercept enables one to determine the work function of the metal and state its numerical value (in eV) without using Planck’s constant.