Magnetic Dipole
The basic magnetic structure created by a closed circulating current loop or intrinsic particle spin, possessing North and South magnetic poles.
Governing formula
μ = I A, τ = μ × B
SI unit
A·m² (or J/T)
In depth
Because isolated magnetic monopoles do not exist, all magnetic field sources in nature (from bar magnets to electrons) behave fundamentally as magnetic dipoles.
Examples in the real world
A current-carrying planar wire loop or an electron orbiting an atomic nucleus acting as a tiny magnetic dipole.