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JEE Mains · Physics · STD 12 - 11. Dual nature of radiation and matter
A beam of light has two wavelengths of \(4972\,\mathop A\limits^o \) and \(6216\,\mathop A\limits^o \) with a total intensity of \(3 .6 \times 10^{- 3}\,\,Wm^{-2}\) equally distributed among the two wavelengths. The beam falls normally on an area of \(1\,cm^2\) of a clean metallic surface of work function \( 2.3\,eV.\) Assume that there is no loss of light by reflection and that each capable photon ejects one electron. The number of photoelectrons liberated in \(2\,s\) is approximately
- A \(6\,\times 10^{11}\)
- B \(9\,\times 10^{11}\)
- C \(11\,\times 10^{11}\)
- D \(15\,\times 10^{11}\)
Answer & Solution
Correct Answer
(B) \(9\,\times 10^{11}\)
Step-by-step Solution
Detailed explanation
Given, \({\lambda _1} = 4972\,\mathop {\text{A}}\limits^o \) and \({\lambda _2} = 6216\,\mathop {\text{A}}\limits^o \) and \(I=3.6 \times 10^{-3}\, \mathrm{Wm}^{-2}\) Intensity associated with each wavelength…
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