Q. A bar magnet of magnetic moment M is bent in ‘⊔’ shape such that all the parts are of equal lengths. Then new magnetic moment is
(a) M/3
(b) 2M
(c) √3 M
(d) 3√3 M
Ans: (a)
Sol: 
When a thin bar magnet of magnetic moment M is bent in the form of ⊔- shape with the arms of equal length , then
Magnetic moment of Each part = M/3
Net magnetic moment of the combination,
$ \displaystyle \vec{M’} = \frac{M}{3}(-\hat{j}) + \frac{M}{3}(\hat{i}) + \frac{M}{3}(\hat{j})$
M’ = M/3