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) to measure. The "maxwell" was affirmed again unanimously as the unit name for magnetic flux at the Plenary Meeting of the International Electrotechnical Commission in July 1930 at Oslo. In 1933, the Electric and Magnetic Magnitudes and Units committee of the International Electrotechnical Commission recommended to adopt the metre-kilogram-second (MKS) system (Giorgi system), and the name weber was proposed for the practical unit of magnetic flux (), subject to approval of various national committees, which was achieved in 1935. The "weber" was thus adopted as a practical unit of magnetic flux by the International Electrotechnical Commission. The "maxwell" is a