JEE Mains · Physics · STD 12 - 11. Dual nature of radiation and matter
Monochromatic light of frequency \(6 \times 10^{14} \mathrm{~Hz}\) is produced by a laser. The power emitted is \(2 \times 10^{-3} \mathrm{~W}\). How many photons per second on an average, are emitted by the source? (Given \(\mathrm{h}=6.63 \times 10^{-34} \mathrm{Js}\) )
- A \(9 \times 10^{18}\)
- B \(6 \times 10^{15}\)
- C \(5 \times 10^{15}\)
- D \(7 \times 10^{16}\)
Answer & Solution
Correct Answer
(C) \(5 \times 10^{15}\)
Step-by-step Solution
Detailed explanation
\(\mathrm{P}=\mathrm{nh \nu}\) \(\mathrm{n}=\frac{\mathrm{P}}{\mathrm{h} \nu}=\frac{2 \times 10^{-3}}{6.63 \times 10^{-34} \times 6 \times 10^{14}}\) \(=5 \times 10^{15}\)
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