A photoelectric cell having an active area of is exposed to monochromatic light of…
PHYSICS · Multi-part · A Level · Physics · Particles and radiation · Particles and radiation
Problem
A photoelectric cell having an active area of 2.0cm2 is exposed to monochromatic light of frequency 8.0×1014Hz. The threshold frequency for the metal is 5.0×1014Hz. The intensity of the light incident on the surface is 1.5mWcm−2. At this intensity the measured saturation photocurrent is 9.6μA.
(i) Calculate the stopping potential for the emitted photoelectrons.
(ii) Predict the new saturation photocurrent if the incident intensity is doubled while all other parameters remain the same.
(iii) Determine the photon flux (number of photons incident per second) on the active area at the original intensity.