A clean potassium surface is illuminated with monochromatic light of wavelength 330 nm
PHYSICS · Multi-part · A Level · Physics · Particles and radiation · Particles and radiation
Problem
A clean potassium surface is illuminated with monochromatic light of wavelength 330 nm. The work function of potassium is 2.25 eV.
(a) Calculate the energy, in electron-volts, of a single photon of the incident light.
(b) Determine the maximum kinetic energy, in electron-volts, of the emitted photoelectrons.
(c) Calculate the magnitude of the stopping potential required to reduce the photocurrent to zero.
(d) If the intensity of the 330 nm light is doubled while all other conditions remain unchanged, explain what happens to (i) the stopping potential and (ii) the maximum kinetic energy of the emitted electrons.