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A beam of electromagnetic radiation of i...

A beam of electromagnetic radiation of intensity `12.8 xx 10^(-5) W//cm^(2)` is comprised of wavelength, `lambda = 155 nm` . It falls normally on a metal (work function `phi = 2eV`) of surfacce area of the ` 1 cm^(2)`. If one in `10^(3)` photons ejects total number of electrons ejected in 1 s in `10^(x)`. (hc = 1240 eVnm) `1eV = 1.6 xx 10^(-19)`J =, then x is _____.

Text Solution

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The correct Answer is:
A
Energy one photon `(hc)/(lamda)=1240/155=8eV`
No of e`=(12.8xx10^(-5)xx1)/(8xx1.6xx10^(-19))xx10^(-)=10^(-5+3+19)=11`
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