Dual Nature Of Light Question 279
Question: If mean wavelength of light radiated by 100 W lamp is 5000 Å, then number of photons radiated per second are [RPET 1997]
Options:
A) $ 3\times 10^{23} $
B) $ 2.5\times 10^{22} $
C) $ 2.5\times 10^{20} $
D) $ 5\times 10^{17} $
Show Answer
Answer:
Correct Answer: C
Solution:
$ P=\frac{nhc}{\lambda t}\Rightarrow \frac{n}{t}=\frac{P.\lambda }{hc}=\frac{100\times 5000\times {{10}^{-10}}}{6.6\times {{10}^{-34}}\times 3\times 10^{8}} $ $ =2.50\times 10^{20} $
BETA
