question_answer

Two metals A and B have work functions \[\mathbf{4}\text{ }\mathbf{eV}\] and \[\mathbf{10}\text{ }\mathbf{eV}\] respectively. Which metal has higher threshold wavelength?

Answer:

                \[{{W}_{0}}=h{{v}_{0}}=\frac{hc}{{{\lambda }_{0}}}\] i.e., \[{{\lambda }_{0}}\propto \frac{1}{{{W}_{0}}}\] So metal A with lower work function has higher threshold wavelength.