Nuclear Physics And Radioactivity Question 32
Question: Consider an electron $ (m=9.1\times {{10}^{-31}}kg) $ confined by electrical forces to move between two rigid walls separated by $ 1.0\times {{10}^{-9}} $ metre, which is about five atomic diameters. The quantised energy value for the lowest stationary state is [ISM Dhanbad 1994]
Options:
A) $ 12\times {{10}^{-20}}Joule $
B) $ 6.0\times {{10}^{-20}}Joule $
C) $ 6.0\times {{10}^{-18}}Joule $
D) 6 Joule
Show Answer
Answer:
Correct Answer: B
Solution:
It will form a stationary wave $ \lambda =2l=2\times {{10}^{-9}}m $
$ \Rightarrow \lambda =\frac{h}{\sqrt{2mE}} $
$ \Rightarrow E=\frac{h^{2}}{2m{{\lambda }^{2}}}=6\times {{10}^{-20}}J $
BETA
