A current loop is considered a magnetic dipole. Explain. Also give an expression for its dipole moment.

Explanation

Consider a plane loop of wire carrying current I as shown in Fig. Looking at the upper face, current is anticlockwise and , therefore , it has a north polarity. Looking at the lower face of the loop, the current is clockwise and hence it has a south polarity. The current loop, thus, behaves as a magnetic dipole.
The magnetic moment `vecm` of a current loop is equal to the product of current I and area A enclosed by the loop. Thus,
`vecm = I vecA`
If instead of a single loop, we have a coil of N turns, then its magnetic moment.
`vec(m) = N I vecA`