PHYSICS · Multi-part · A Level · Physics · Particles and radiation · Particles and radiation
Problem
For a photoelectric cell, the threshold frequency of the emitter is 5.0×1014Hz. When light of frequency 8.0×1014Hz is used, the stopping potential is 3.0V. The frequency of the light is then reduced by 10% while its intensity is kept the same.
(i) Calculate the new stopping potential.
(ii) Determine the percentage decrease in the maximum kinetic energy of the emitted electrons.