Meaning of REACTANCE in English



Measure of the opposition that an electrical circuit or a part of a circuit presents to electric current (see electrical impedance ) insofar as the current is varying or alternating.

Steady electric currents flowing along conductors in one direction undergo opposition called electrical resistance , but no reactance. Reactance is present in addition to resistance when conductors carry alternating current . Reactance also occurs for short intervals when direct current is changing as it approaches or departs from steady flow (e.g., when switches are closed or opened). Reactance is of two types, inductive and capacitive. Inductive reactance is associated with the varying magnetic field that surrounds a wire or a coil carrying a current. Capacitive reactance is associated with the changing electric field between two conducting surfaces (plates) separated from each other by an insulating medium. The ohm is the unit of reactance.

Britannica Concise Encyclopedia.      Краткая энциклопедия Британика.