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
David Davies (electrical engineer) (IEE) 1996-2001, President of the Royal Academy of Engineering He has subsequently been Chairman of Railway Safety, a non executive director of Lattice plc, a non-executive director of The ERA Foundation, Chairman of the Hazards Forum (2002-2010), and safety advisor to the Board of National Grid plc. The Sir David Davies building at Loughborough University, housing the electrical engineering department, is now named after him. David Davies (electrical engineer) Sir David Evan Naunton Davies , known as Den Davies or David "DEN" Davies, (born 1935) is a British electrical engineer and educator. He was knighted for services to science in