Physics

Problem

Light of wavelength

400\,\text{nm}

falls on a metal surface that has a threshold wavelength of

550\,\text{nm}

. Determine the stopping potential required to just stop the most energetic photo-electrons. (Take

h = 6.63\times10^{-34}\,\text{J s}

c = 3.0\times10^{8}\,\text{m\,s}^{-1}

e = 1.6\times10^{-19}\,\text{C}