Thank you for reporting, we will resolve it shortly
Q.
A bar magnet of length '$l$' and magnetic dipole moment 'M' is bent in the form of an arc as shown in figure. The new magnetic dipole moment will be
Let magnetic pole strength be m then
M$ = m \ell$
In new situation
$M' = (m) \left(2r \,\,sin \frac{60^\circ}{2}\right) where\, \, r \left( \frac{\pi}{3}\right) = \ell$
$M' = 2m \left(\frac {2 \ell}{\pi}\right) \left(\frac{1}{2}\right) = \frac{3m\ell}{\pi} = \frac {3M}{\pi}$
