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JEE Mains · Physics · STD 12 - 11. Dual nature of radiation and matter
A parallel beam of light of wavelength \(900\,nm\) and intensity \(100\,Wm ^{-2}\) is incident on a surface perpendicular to the beam. Tire number of photons crossing \(1\,cm ^{2}\) area perpendicular to the beam in one second is :
- A \(3 \times 10^{16}\)
- B \(4.5 \times 10^{16}\)
- C \(4.5 \times 10^{17}\)
- D \(4.5 \times 10^{20}\)
Answer & Solution
Correct Answer
(B) \(4.5 \times 10^{16}\)
Step-by-step Solution
Detailed explanation
Wavelength of incident beam \(\lambda=900 \times 10^{-9}\,m\) Intensity of incident beam \(= I =100\,W / m ^{2}\) No. of photons crossing per unit sec \(= n =\frac{ E _{\text {net }}}{ E _{\text {sim gle photon }}}=\frac{ IA \lambda}{ hc }\)…
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