Dual Nature Of Radiation

A metal exposed to light of wavelength \(800 \mathrm{~nm}\) and and emits photoelectrons with a certain kinetic energy. The maximum kinetic energy of photo-electron doubles when light of wavelength \(500 \mathrm{~nm}\) is used. The workfunction of the metal is : (Take hc \(=1230 \,\mathrm{eV}-\mathrm{nm}\) ).