Monochromatic light of wavelength and power is uniformly incident on a photoemissive…

PHYSICS · Subjective · A Level · Physics · Particles and radiation · Particles and radiation

Problem

Monochromatic light of wavelength

310\,\text{nm}

and power

12\,\text{mW}

is uniformly incident on a photoemissive surface of area

2.0\,\text{cm}^2

. The quantum efficiency of the surface is

25\%

, and every emitted electron is collected. Calculate the saturation current produced. (Use

h = 6.63 \times 10^{-34}\,\text{J}\,\text{s}

c = 3.0 \times 10^{8}\,\text{m}\,\text{s}^{-1}

e = 1.6 \times 10^{-19}\,\text{C}