Physics - Modern Physics Question with Solution | TestHub

In the photoelectric effect, energy is conserved

In the photoelectric effect, Einstein's equation is given by

Photon energy = kinetic energy of electron + work function

i.e.$h\nu =e{V}_S+h{\nu }_0$

where,$V_S$is the stopping potential and${\nu }_0$is the threshold frequency

$\therefore V_S=\frac{h}{e}\left(\nu -{\nu }_0\right)$.... (i)

Given,${\nu }_0=3.3\times {10}^{14} \mathrm{Hz}, \nu =8.2\times {10}^{14} \mathrm{Hz}$

$h=6.6\times {10}^{-34}\mathrm{ }\mathrm{J} \mathrm{s} , e=1.6\times {10}^{-19}C$

Substituting these values in equation (i). we get

$V_S=\frac{6.6\times {10}^{-34}\left(8.2\times {10}^{14}-3.3\times {10}^{14}\right)}{1.6\times {10}^{-19}}$

$V_S=\frac{6.6\times 4.9}{1.6}\times {10}^{-1}=2 \mathrm{V}$

$\Rightarrow V_S=2 \mathrm{V}$