magnetic dipole

A model of an object that generates a magnetic field in which the field is considered to emanate from two opposite poles, as in the north and south poles of a magnet, much as an electric field emanates from a positive and a negative charge (each of which is a monopole) in an electric dipole. Even though the existence of magnetic monopoles as isolable particles has not been established, the magnetic dipole remains a useful simplification of the electrodynamics involved in magnetism. Magnetic dipoles experience torque in the presence of magnetic fields.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.