Physics - Modern Physics Question with Solution | TestHub

Work function $W_0=3.31\times 10^{-19}\mathrm{J}$ Wavelength of incident radiation $\lambda =5000\times 10^{-10}\mathrm{m}$ According to Einstein's photoelectric equation $E=W_0+KE$ $\begin{array}{rl}\Rightarrow \frac{hc}{\lambda }& =3.31\times 10^{-19}+\mathrm{KE}\\ \mathrm{KE}& =-3.31\times 10^{-19}+\frac{6.62\times 10^{-34}\times 3\times 10^8}{5000\times 10^{-10}}\\ & =-3.31\times 10^{-19}+\frac{6.62\times 3}{5}\times 10^{-19}\\ & =(-3.31\times 1.324\times 3)\times 10^{-19}\end{array}$ $\begin{array}{rl}& =(3.972-3.31)\times 10^{-19}\\ & =0.662\times 10^{-19}\mathrm{J}\\ \text{ or }E& =\frac{0.662\times 10^{-19}}{1.6\times 10^{-19}}=0.41\mathrm{eV}\end{array}$