Physics · 2014
JEE Main · 12 April 2014, Shift 1 · Q26
A beam of light has two wavelengths 4972 and 6216 with a total intensity of 3.6 × 10^-3 Wm^-2 equally distributed among the two wavelengths. The beam…
A beam of light has two wavelengths $\displaystyle 4972 \AA$ and $\displaystyle 6216 \AA$ with a total intensity of $\displaystyle 3.6 \times 10^{-3} \mathrm{Wm}^{-2}$ equally distributed among the two wavelengths. The beam falls normally on an area of $\displaystyle 1 \mathrm{~cm}^2$ of a clean metallic surface of work function $\displaystyle 2.3$ eV . Assume that there is no loss of light by reflection and that each capable photon ejects one electron. The number of photo electrons liberated in 2s is approximately :
Official answer
(2)
$\displaystyle 9 \times 10^{11}$
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JEE Main 2014 Physics question, with the answer from NTA’s final answer key. Where our answers come from.