## Current Loop as Magnetic Dipole:

Consider a plane loop of wire carrying current. Looking at the upper face, the current is anti-clockwise. Therefore, the upper face will become N-pole. Looking at the lower face of the loop, the current is clockwise. Therefore, the lower face will become the South pole. Hence the current-carrying loop behaves as a magnetic dipole.

The magnetic dipole moment (M) of the current loop is directly proportional to-

- Strength of current (I) through the loop.
- Area (A) is enclosed by the loop.

i.e. M ∝ I and M ∝ A Combine these two factors M ∝ IA ⇒ M = KIA In S.I. Units, K = 1 ⇒ M = IA If the current loop has N turns, then ⇒ M = NIA The S.I. Unit of M is Ampere-metre ^{2}. One Ampere-metre^{2} is the magnetic moment of one turn loop of area one square metre carrying a current of one ampere. |