IMPEDANCE

add. ·noun the apparent resistance in an electric circuit to the flow of an alternating current, analogous to the actual electrical resistance to a direct current, being the ratio of electromotive force to the current. it is equal to r2 + x2, where r ohmic resistance, x reactance. for an inductive circuit, x 2/fl, where f frequency and l self-inductance; for a circuit with capacity x 1 / 2/fc, where c capacity.