Question

What is the threshold frequency of metal if its work function is 4.0 eV and wavelength of 700nm is incident on it?

Answer 1

Solution

Work function is given by

$\phi=\frac{hc}{\lambda_0}=4.0eV$

$\lambda_0=\frac{1240eV-nm}{4.0eV}=3100A^0$