Question

Obtain the relation for magnetic dipole moment `vec M` of current carrying coil. Give the direction of `vec M`.

Answer 1

Let a coil have current I, number of turns N, and area of each loop A.

The magnetic dipole moment for a single loop is given by:

M = IA_n

Where A is the area enclosed by the loop (A = πR² for a circular coil), and n is the unit normal vector to the plane of the loop (direction given by the right-hand rule).

If the coil has N turns, the total magnetic dipole moment is:

M = NIA_n

The direction of M is perpendicular to the plane of the coil and given by the right-hand rule.