Maximum Angular Frequency $=6.28 \times 10^7 \times 3 \times 10^8 \mathrm{rad} / \mathrm{s}$ $$ \begin{aligned} & \Rightarrow f_{\max }=3 \times 10^{15} \mathrm{~Hz} \\ & E_{\max }=h f_{\operatorname{nax}}=\frac{6.6 \times 10^{-34} \times 3 \times 10^{15}}{1.6 \times 10^{-19}} \mathrm{ev} \\ & =12.375 \mathrm{ev} \square 12.38 \mathrm{eV} \\ & \Rightarrow K E_{\max }=12.38-4.7 \square 7.7 \mathrm{eV} \end{aligned} $$