Monochromatic blue light of wavelength nm falls on the caesium cathode of a vacuum…
PHYSICS · Multi-part · Fermi University Physics · Quantum Mechanics · Origins of quantum theory · Origins of quantum theory
Quantum Mechanics: From the Photon to the Hydrogen Atom, Ch Light in lumps: blackbody radiation, the photoelectric effect and Compton scattering
Problem
Monochromatic blue light of wavelength 450 nm falls on the caesium cathode of a vacuum photocell. Caesium has work function W=2.14 eV. Each electron that escapes absorbs one whole photon, and contact potentials in the cell are ignored.
((a)) Find the energy of one photon of this light, in electronvolts.
((b)) Find the momentum of one such photon, in kg m s−1.
((c)) Find the stopping potential of the cell.