Resistance See also: Conduction; Impedance; Ohm's Law; Resistor Superconductivity Property of an electric Conductor which it opposes flow of Electricity and dissipates electrical Energy away from the Electric Circuit, usually as Heat. Resistance is basically the same for Alternating Current (AC) and Direct Current (DC) circuits. A high-Frequency alternating current, however, tends to travel near the surface of a conductor (see Skin Effect). Because such a current uses less of the available cross section of the conductor, it meets with more resistance than direct current. The unit of resistance is the Ohm.