Monochromatic light of frequency (where is the metal’s threshold frequency) shines on…
PHYSICS · Single correct · A Level · Physics · Particles and radiation · Particles and radiation
Problem
Monochromatic light of frequency 0.90fth (where fth is the metal’s threshold frequency) shines on a clean metal surface. The intensity of the light is steadily increased by a factor of 100. Which outcome is most consistent with the photoelectric effect?
(a) Electrons begin to be emitted once the intensity is high enough because they can add the energies of multiple photons.
(b) No electrons are emitted at any intensity because each photon lacks sufficient energy to overcome the work function.
(c) Electrons are emitted, and the emission rate increases with intensity while their maximum kinetic energy remains unchanged.
(d) Electrons are emitted only after a measurable time delay, during which an electron absorbs enough energy from successive photons.