(Åmz) a mathematical relationship formulated by the German physicist Georg Simon Ohm in 1826, comparing voltage (V), current (I), and resistance (R), usable for either alternating current or direct current . It originally applied only to situations of steady direct current, with the formula V = IR; with alternating current, the electrical circuit contains resistors, inductors, and capacitors and the formula becomes V = IZ, where Z is a complex number representing the impedance .
