electrical impedance [i`lek·trǝ·kǝl im`pēd·ǝns] ELECTRICITY 1. The total opposition that a circuit presents to an alternating current, equal to the complex ratio of the voltage to the current in complex notation. Also known as complex impedance. 2. The ratio of the maximum voltage in an alternating-current circuit to the maximum current; equal to the magnitude of the quantity in the first definition. |