Question

A photon of wavelength 4 × 10^–7 m strikes on metal surface, the work function of the metal being 2.13 eV. Calculate
(i) the energy of the photon (eV),
(ii) the kinetic energy of the emission, and
(iii) the velocity of the photoelectron (1 eV= 1.6020 × 10^–19 J).

Answer 1

The velocity of a photoelectron (ν) can be calculated by the expression,

Where(hv-hv) is the kinetic energy of emission in Joules and ‘m’ is the mass of the
photoelectron. Substituting the values in the given expression of v:

Hence, the velocity of the photoelectron is 5.84 × 10⁵ ms^–1.