A magnetic field is a vector field that describes the magnetic influence of electric charges in relative motion and magnetized materials. The effects of magnetic fields are commonly seen in permanent magnets, which pull on magnetic materials (such as iron) and attract or repel other magnets.

The magnetic field is characterized by some magnitudes. The stronger is the magnetic field of a magnet, the greater is the magnetic field flux density associated with the magnet poles. The magnetic field flux through a surface in SI system is measured in Weber (Wb).

Wilhelm Eduard Weber (24 October 1804 – 23 June 1891) was a German physicist. One of his most important works, co-authored with Carl Friedrich Gauss and Carl Wolfgang Benjamin Goldschmidt, was Atlas of Geomagnetism: Designed according to the elements of the theory, a series of magnetic maps. He studied magnetism with Gauss, and during 1864 published his Electrodynamic Proportional Measures containing a system of absolute measurements for electric currents, which forms the basis of those in use. Weber died in Göttingen, where he is buried in the same cemetery as Max Planck and Max Born.

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