(a) Give an example each of a metal from which photoelectric emission takes place when irradiated by (i) UV light (ii) visible light. (b) The work…

From Einstein for equation of photo electric effect

$$\mathrm{h} v=\mathrm{W}_{\mathrm{o}}+\mathrm{KE}_{\max }

$$$$ =$\displaystyle 4.5$ \times $\displaystyle 1.6$ \times $\displaystyle 10$^{-$\displaystyle 19$}+$\displaystyle 6.06$ \times $\displaystyle 10$^{-$\displaystyle 19$}

$$$$ =($\displaystyle 7.2$+$\displaystyle 6.06$) \times $\displaystyle 10$^{-$\displaystyle 19$} \mathrm{~J}

$$$$ =$\displaystyle 13.26$ \times $\displaystyle 10$^{-$\displaystyle 19$} \mathrm{~J}

$$$$ \begin{aligned} v= & \frac{$\displaystyle 13.26$ \times $\displaystyle 10$^{-$\displaystyle 19$}}{$\displaystyle 6.6$ \times $\displaystyle 10$^{-$\displaystyle 34$}} & =$\displaystyle 2$ \times $\displaystyle 10$^{$\displaystyle 15$} \mathrm{~Hz} \end{aligned}