

Wavelength of light produced by the argon laser,
= 488 nm
m
Stopping potential of the photoelectrons,
= 0.38 V
1eV
J
∴
= 
Planck’s constant, h
Js
Charge on an electron, e= 1.6 × 10 – 19C
Speed of light, c= 3 × 10 m/s
From Einsteins photoelectric effect, we have the relation involving the work function
of the material of the emitter as:





Therefore, the material with which the emitter is made has the work function of 2.16 eV.
