Magnetic dipole magnetic dipole as the distance from the source increases. In classical physics, the magnetic field of a dipole is calculated as the limit of either a current loop or a pair of charges as the source shrinks to a point while keeping the magnetic moment constant. For the current loop, this limit is most easily derived for the vector potential. Outside of the source region, this potential is (in SI units) with 4"π r" being the surface of a sphere of radius "r"; and the magnetic flux density (strength of the B-field) in teslas is In spherical coordinates with the
Maxwell (unit) Maxwell (unit) The maxwell (symbol: Mx) is the CGS (centimetre-gram-second) unit of magnetic flux (). The unit name honours James Clerk Maxwell, who presented a unified theory of electromagnetism. The "maxwell" was recommended as a CGS unit at the International Electrical Congress held in 1900 at Paris. This practical unit was previously called a "line", reflecting Faraday's conception of the magnetic field as curved lines of magnetic force, which he designated as "line of magnetic induction". "Kiloline" (10 line) and "megaline" (10 line) were sometimes used because 1 line was very small relative to the phenomena that it was used