(a) Define the terms (i) saturation photocurrent and (ii) stopping potential in the…
PHYSICS · Subjective · A Level · Physics · Particles and radiation · Particles and radiation
Problem
(a) Define the terms (i) saturation photocurrent and (ii) stopping potential in the context of the photoelectric effect.
(b) Draw a clearly-labelled, qualitative graph showing the variation of photocurrent I with the applied potential difference V for monochromatic radiation of frequency greater than the threshold frequency incident on a clean metallic surface. Mark on the graph:
(i) the rising region,
(ii) the saturation region,
(iii) the point corresponding to the stopping potential.
(c) Explain briefly why the photocurrent attains a constant value at large positive collector potentials even though the emitted electrons continue to gain additional kinetic energy.