Question

Light of wavelength 2400Å falls on a metal surface of work function 3.6eV. What is the kinetic energy (in eV) of (i) the fastest and (ii) the slowest electrons emitted from the surface? If the same light falls on another surface of work function 5.5eV, what will be the energy of emitted electrons?

Answer 1

λ = 2400Å = 2400 x10^-10m, work function (W₀) =3.6eV

(i) K.E. of fastest electron =1.58eV
(ii) K.E. of slowest electron = 0eV
If the same light (having energy 5. 18eV) falls on the surface of work function 5. 5eV, then no photoelectron will emit.​