Helmholtz coils

Helmholtz coils

A pair of flat circular coils with equal numbers of turns and equal diameters, arranged with a common axis, and connected in series to have a common current (see illustration). The purpose of the arrangement is to obtain a magnetic field that is more nearly uniform than that of a single coil without the use of a long solenoid. The optimum arrangement is that in which the distance between the two coils is equal to the radius of one of the coils.

Helmholtz coils separated by distance r , resulting in a nearly uniform field of point P Helmholtz coils separated by distance r, resulting in a nearly uniform field of point P

Helmholtz coils

[′helm‚hōlts ‚kȯilz] (electromagnetism) A pair of flat, circular coils having equal numbers of turns and equal diameters, arranged with a common axis, and connected in series; used to obtain a magnetic field more nearly uniform than that of a single coil.