A square current carrying loop of side ’a’ produced magnetic field at its centre is ’B’. Find magnetic moment of this loop in terms of ’B’.

A wire of length '$\mathcal{l}$’ carries a current bent into various regular polygons shown below. Find magnetic moment in terms of length of the wire. Circular loop.

Four wires each of length $2.0 \mathrm{m}$, are bent in four-loop $P,Q,R$ and $S$ then suspended in uniform magnetic field. All loop carries equal currents, which statement of the following is true :