A clean sodium surface is irradiated by monochromatic light of frequency (greater…
PHYSICS · Multi-part · A Level · Physics · Particles and radiation · Particles and radiation
Problem
A clean sodium surface is irradiated by monochromatic light of frequency 6.5×1014Hz (greater than the threshold frequency for sodium). The intensity of the incident light is then suddenly doubled while all other experimental conditions are kept unchanged.
(i) Sketch the two I–V curves on the same axes, labelling Isat,1, Isat,2, and the common stopping potential V0.
(ii) State and justify which parameter (Isat or V0) is altered by the change in intensity and why the other parameter remains unchanged.