Computed drawings of four different types of magnetic dipoles.Upper left: An ideal point-like dipole. The field shape is scale invariant and approximates the field of any magnetized volume with nonzero dipole moment at large distance.
Upper right: Discrete dipole of two opposite point-like magnetic poles at finite distance, a physical dipole. Note that isolated magnetic charges don't exist, but this configuration accurately represents the field of a very thin magnetized rod with magnetic poles at each end.
Lower left: Circular ring conductor loop with electric an current. An “Amperian loop”.
Lower right: Ideal continuous solenoid, a hollow cylinder with uniform circular current sheet around its circumference. This equally represents the B-field of a uniformely magnetized cylinder magnet.
Although the four field configurations differ significantly, they all converge to the same dipole field at large distances. Each configuration may represent a magnetic dipole.
Own work
Geek3