Dual Nature Of Radiation And Matter Ques 43
43. Monochromatic light of frequency $6.0 \times 10^{14}$ $ Hz$ is produced by a laser. The power emitted is $2 \times 10^{-3}$ $ W$. The number of photons emitted, on the average, by the sources per second is
[2007]
(a) $5 \times 10^{16}$
(b) $5 \times 10^{17}$
(c) $5 \times 10^{14}$
(d) $5 \times 10^{15}$
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Answer:
Correct Answer: 43.(d)
Solution:
- (d) Since $p=n h v$
$ \Rightarrow n=\frac{p}{h v}=\frac{2 \times 10^{-3}}{6.6 \times 10^{-34} \times 6 \times 10^{14}}=5 \times 10^{15} $
BETA
