Magnetic field
A magnetic field is a vector field that describes the magnetic influence of electrical currents and magnetized materials. In everyday life, the effects of magnetic fields are often seen in permanent magnets, which pull on magnetic materials (such as iron) and attract or repel other magnets. Magnetic fields surround and are created by magnetized material and by moving electric charges (electric currents) such as those used in electromagnets. Magnetic fields exert forces on nearby moving electrical charges and torques on nearby magnets. In addition, a magnetic field that varies with location exerts a force on magnetic materials. Both the strength and direction of a magnetic field varies with location. As such, it is an example of a vector field.
Magnetic field
The term 'magnetic field' is used for two distinct but closely related fields denoted by the symbols and . In the International System of Units, is measured in units of amperes per meter and is measured in teslas, which are equivalent to newtons per meter per ampere. and differ in how they account for magnetization. In a vacuum, and are the same aside from units; but in a magnetized material, /formula_1 and differ by the magnetization of the material at that point in the material.