Dual Nature Of Light Question 366
Question: An ultraviolet light bulb, emitting 400 nm and an infrared light bulb, emitting at 700nm, each are rated at 130 W. Then the ratio of the number of photons emitted per second by the UV and IR sources is -
Options:
A) 0.57
B) 1.75
C) 28
D) 0.04
Show Answer
Answer:
Correct Answer: A
Solution:
[a] Use $ n=\frac{1}{hv}=\frac{I\lambda }{hc} $
$ \therefore \frac{n_{UV}}{n_{IR}}=\frac{{\lambda_{UV}}}{{\lambda_{IR}}}=\frac{400}{700}=\frac{4}{7}=0.57 $
BETA
