polarity The positive (+) or negative (–) property of an electrical charge. Opposite electrical conditions determine the direction in which discharged electrical current tends to flow, from positive to negative. Direct current (DC) flows in one direction along a circuit, as the positive and negative poles are fixed at either end of the circuit. Alternating current (AC) flows first in one direction and then in the other, as the polarity reverses. See also AC and DC. |