Physics - Modern Physics Question with Solution | TestHub

From Planck's quantum theory, the maximum kinetic energy (Ek) of photoelectron emitted from the metal is

${ E}_k=hf-W$

Where W is the work function of metal and$hf$is the energy of the photon absorbed by the metal.

Given,$hf=2\mathrm{ }\mathrm{eV}, W=1.4 \mathrm{eV}$

$\therefore E_k=2-1.4=0.6$$\mathrm{eV}$

Hence, stopping potential is ,$V_s=\frac{E}{e}=\frac{0.6 \mathrm{e}\mathrm{V}}{e}=0.6\mathrm{ }\mathrm{V}.\mathrm{ }$