Dual Nature Of Light Question 418
Question: The de-Broglie wavelength of an electron having $ 80eV $ of energy is nearly ( $ 1,eV=1.6\times 10^{19}J, $ Mass of electron $ =9\times {{10}^{-31}}kg $ PlankΒs constant $ =6.6\times {{10}^{-34}}J\text{-},\sec $ )
Options:
A) 140 $ \overset{o}{\mathop{A}}, $
B) 0.14 $ \overset{o}{\mathop{A}}, $
C) 14 $ \overset{o}{\mathop{A}}, $
D) 1.4 $ \overset{o}{\mathop{A}}, $
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Answer:
Correct Answer: B
Solution:
[b] If an electron and a photon propagates in the from of waves having the same wavelength, it implies that they have same momentum. This is according to de-Broglie equation, $ p\propto \frac{1}{\lambda } $