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A beam of light having wavelength lambda...

A beam of light having wavelength `lambda ` and intensity 1 falls normally on an area A of a clean surface then
find out the number of photon incident on the surface.

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Total energy incident in time `t = IA t `
Energy of one photon `E =( hc)/( lambda)`
Then number of photon incident in time t `= ("Total energy incident") /( "energy of one photon") = (IAt lambda)/( hc)`
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MOTION-MODERN PHYSICS -1-EXERCISE-4 ( LEVEL- II)
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