Dual Nature of matter and Radiation Part 2

A photoemissive substance is illuminated with a radiation of wavelength λi so that it releases electrons with de-Broglie wavelength λe. The longest wavelength of radiation that can emit photoelectron is λ0. Expression for de-Broglie wavelength is given by:
( m : mass of the electron, h : Planck's constant and c : speed of light)