Write Einstein's photoelectric equation

Write Einstein’s photoelectric equation. Explain the terms (i) threshold frequency and (ii) stopping potential. [Delhi Comptt. I, II, III 2013][OD I, II, III, 2012]

Einstein’s photoelectric equation,
K.E. of photo electron
= Incident energy of photons -Work function
or K.E.=$hv-{{W}{0}}$
or K.E.=$hv-h{{v}
{0}}$
where ${{v}{0}}$ is called threshold frequency.
(i) Threshold Frequency : For a given metal, there exists a certain minimum frequency of the incident radiation below which no emission of photoelectrons takes place. This frequency is called threshold frequency.
(ii) Stopping Potential : It is that minimum negative potential given to anode in a photocell for which the photoelectric current becomes zero. It is denoted by ${{V}
{0}}$. It is independent of the intensity of the incident light.