Dual Nature Of Light Question 108
Question: A photon of wavelength 6630 Å is incident on a totally reflecting surface. The momentum delivered by the photon is equal to
Options:
A) 6.63 ´ 10?27 kg-m/sec
B) 2 ´ 10?27 kg-m/sec
C) 10?27 kg-m/sec
D) None of these
Show Answer
Answer:
Correct Answer: B
Solution:
The momentum of the incident radiation is given as $ p=\frac{h}{\lambda } $ . When the light is totally reflected normal to the surface the direction of the ray is reversed. That means it reverses the direction of it?s momentum without changing it?s magnitude \ $ \Delta p=2p=\frac{2h}{\lambda }=\frac{2\times 6.6\times {{10}^{-34}}}{6630\times {{10}^{-10}}} $ = 2 ´ 10?27 kg-m/sec.
BETA
