For a certain metal surface the threshold wavelength is
PHYSICS · Subjective · A Level · Physics · Particles and radiation · Particles and radiation
Problem
For a certain metal surface the threshold wavelength is 560nm. Ultraviolet light of wavelength 350nm is made to fall normally on the surface at an intensity of 1.2Wm−2.
(i) Calculate the maximum kinetic energy of the emitted photoelectrons in electron-volts.
(ii) Determine the stopping potential required to reduce the photocurrent to zero.
(iii) If the intensity of the ultraviolet light is tripled while its wavelength remains unchanged, what changes, if any, occur in the answers obtained in parts (i) and (ii)? Give numerical values where appropriate.