Neet Solved Paper 2013 Question 30
Question: A bar magnet of length I and magnetic dipole moment M is bent in the form of an arc as shown in figure. The new magnetic dipole moment will be
Options:
A) M
B) $ \frac{3}{\pi }M $
C) $ \frac{2}{\pi }M $
D) $ \frac{M}{2} $
Show Answer
Answer:
Correct Answer: B
Solution:
- The magnetic moment, M = ml $ l=\frac{\pi }{3}\times r $ or $ r=\frac{3l}{\pi } $
$ \therefore $ New magnetic moment $ M’=m\times r $ $ =m\times \frac{3l}{\pi }=\frac{3}{\pi }.ml=\frac{3M}{\pi } $
