JEE Main On 8 April 2017 Question 16
Question: According to Bohr’s theory, the time averaged magnetic field at the centre (i.e. nucleus) of a hydrogen atom due to the motion of electrons in the $ {n^{th}} $ orbit is proportional to : (n = principal quantum number) [JEE Online 08-04-2017]
Options:
A) $ {n^{-3}} $
B) $ {n^{-2}} $
C) $ {n^{-4}} $
D) $ {n^{-5}} $
Show Answer
Answer:
Correct Answer: B
Solution:
- $ B=\frac{{\mu_0}I}{2r} $ $ =\frac{{\mu_0}qt}{2r} $ $ r\propto n^{2} $ $ B\propto {n^{-2}} $
