Atomic Structure Question 42
Question: The mass of a photon with a wavelength equal to $ 1.54\times {10^{-8}}cm $ is [Pb. PMT 2004]
Options:
A) $ 0.8268\times {10^{-34}}kg $
B) $ 1.2876\times {10^{-33}}kg $
C) $ 1.4285\times {10^{-32}}kg $
D) $ 1.8884\times {10^{-32}}kg $
Show Answer
Answer:
Correct Answer: C
Solution:
We know that $ \lambda =\frac{h}{mv} $ ;
$ \therefore $ $ m=\frac{h}{m\lambda } $ The velocity of photon (v) = $ 3\times 10^{8}m{{\sec }^{-1}} $
$ \lambda =1.54\times {10^{-8}}cm=1.54\times {10^{-10}}meter $
$ \therefore $ $ m=\frac{6.626\times {10^{-34}}Js}{1.54\times {10^{-10}}m\times 3\times 10^{8}m,{{\sec }^{-1}}} $
$ =,1.4285\times {10^{-32}}kg $ .
