Physics - Modern Physics Question with Solution | TestHub

A photon of wavelength 3315 Ã… falls on a photocathode and an electron of energy $3\times 10^{-19}\mathrm{J}$ is ejected. The threshold wavelength of photon is [Planck's constant (h) $=6.63\times 10^{-34}\mathrm{J}-\mathrm{s}$, velocity of light $(\mathrm{c})=3\times 10^8\mathrm{m}/\mathrm{s}]$