The incremental susceptibility in anisotropic materials over-all may be described by means of a matrix. The coefficients of the matrix are dependent on the magnitude and direction of the bias. These coefficients can be determined from the field vectors

and

The latter were measured in a cold rolled 50 percent Fe-Ni alloy with cubical texture. The fields can be influenced according to magnitude and direction by means of a bias. A turning of the field direction caused by a bias enables a connection or disconnection of transmission windings. This permits the construction of a switching device.