The stopping potential introduces the voltage difference needed to stop electrons (e) from flowing between two metal plates and creating a current in the photoelectric experiment.
Although, the stopping potential or stopping voltage is used to determine the kinetic energy (K) that the electrons (e) have as they are emitted from the metal plate. The stopping voltage is denoted by Vo.
Stopping potential Equation
You can find here stopping potential or stopping voltage equation, which is given below:
Calculate the stopping potential
Q1 :The work function of metal is 2.14 eV. And the light of frequency 6 x 1014 Hz is moving on the metal surface, photoemission of electrons occurs. Find the stopping potential.
Work function of metal,Φ0 = 2.14 eV
Frequency v = 6.0 x 1014 Hz
As we know,
K = hv – Φ0
h= Planck’s constant = 6.626 ×10-34Js
Hence, the maximum kinetic energy of the emitted electrons is
For stopping potential, as we know the equation for kinetic energy as:
So, the stopping potential of the material is 0.345 V.