Question

A thin bar magnet has magnetic dipole moment m is bent at mid point so that angle between both the parts is 60

Answer 1

Answer:

Let m be the strength of each pole of bar magnet of length l.

M=m\times l

when bar magnet bent in the form of an arc.

l=\frac{\pi }{3}\times r=\frac{\pi r}{3}

r=\frac{3l}{\pi }

new magnetic dipole moment

M^{'}=m\times 2r\sin 30^{\circ}

=m\times2\frac{3l}{\pi }\frac{1}{2}

M^{'}=\frac{3ml}{\pi }

=\frac{3M}{\pi }