A light beam, $\mathrm{E}=100\left[\sin \left({\mathrm{\omega }}_1\mathrm{t}\right)+\sin \left({\mathrm{\omega }}_2\mathrm{t}\right)\right]{\mathrm{Vm}}^{-1}\text{ with }{\mathrm{\omega }}_1=5\times {10}^{15}{\mathrm{s}}^{-1}\text{ and }{\mathrm{\omega }}_2=8\times {10}^{15}{\mathrm{s}}^{-1}$ , falls on a metal surface of work function 2.0 eV. Maximum KE(in eV) of emitted photoelectrons  is __

Higher frequency light causes photoemission of electron with largest kinetic energy $\mathrm{f}=\frac{\mathrm{\omega }}{2\mathrm{\pi }}=\frac{8\times {10}^{15}}{2\mathrm{\pi }}{\mathrm{s}}^{-1}$
Maximum kinetic energy of photoelectrons is,
$\begin{array}{l}{\mathrm{K}}_{max}=\mathrm{hf}-{\mathrm{\varphi }}_0=\frac{4.14\times {10}^{-15}\times 8\times {10}^{15}}{2\mathrm{\pi }}-2.0\\ =5.27-2.0=3.27\mathrm{eV}\end{array}$