Physics

Problem

Monochromatic light of wavelength

400\,\text{nm}

is incident on a metal surface whose work function is

2.0\,\text{eV}

. What is the stopping potential required to just halt the most energetic emitted electrons?

(h=6.6\times10^{-34}\,\text{J s},\;c=3.0\times10^{8}\,\text{m s}^{-1},\;e=1.6\times10^{-19}\,\text{C})

3.1\,\text{V}

1.1\,\text{V}

0.5\,\text{V}

2.0\,\text{V}