A monochromatic light source of intensity 5 mW emits 8 × 1015 photons per second. This light ejects photoelectrons from a metal surface. The stopping potential for this setup is 2.0 V. Calculate the work function of the metal.
Given, intensity I =5mW,
No. of photons emitted per second n=
Stopping potential V =2V
From Einstein’s photoelectric equation,
⇒ work function
⇒
=
=
∴ Work function Ф =1.906eV