Magnetic reactance is the parameter of a passive magnetic circuit or its element, which is equal to the square root of the difference of squares of the full and effective magnetic resistance for a magnetic current, taken with the sign plus, if the magnetic current lags behind the magnetic tension in phase, and with the sign minus, if the magnetic current leads the magnetic tension in phase.
Magnetic reactance  is the component of complex magnetic impedance of the alternating current circuit, which produces the phase shift between a magnetic current and magnetic tension in the circuit. It is measured in units of  and is denoted by (or ). It may be inductive or capacitive , where is the angular frequency of a magnetic current, is the magnetic inductivity of a circuit, is the magnetic capacitivity of a circuit. The magnetic reactance of an undeveloped circuit with the inductivity and the capacitivity, which are connected in series, is equal: . If , then the sum reactance and resonance takes place in the circuit. In the general case . When an energy loss is absent () . The angle of the phase shift in a magnetic circuit . On a complex plane, the magnetic reactance appears as the side of the resistance triangle for circuit of an alternating current.
- ↑ Pohl, R. W. (1960) (in German). Elektrizitätslehre. Berlin-Gottingen-Heidelberg: Springer-Verlag.
- ↑ Popov, V. P. (1985) (in Russian). The Principles of Theory of Circuits. M.: Higher School.
- ↑ Küpfmüller, K. (1959) (in German). Einführung in die theoretische Elektrotechnik. Berlin-Gottingen-Heidelberg: Springer-Verlag.