The abwatt (symbolized abW) is the unit of power in the cgs (centimeter/gram/second) electromagnetic system of units. In a direct-current (DC) circuit, 1 abW is the power dissipated, radiated, or expended when one abvolt (1 abV) of potential difference drives a current of one abampere (1 abA) through a component. In a DC circuit, or in an alternating-current (AC) circuit in which there is no reactance, the following formula holds: P = EI where P is the power in abwatts, E is the potential difference in abvolts, and I is the current in abamperes. The abwatt is a small unit of power, equivalent to 10 ^-7 watt (W) or 0.1 microwatt (W). The abwatt, by coincidence, is the same size as the statwatt (statW), the unit of power in the cgs electrostatic system of units. But in most applications, the watt, which is the unit of power in the International System of Units (SI), is preferred. Also See: Power, watt, cgs or small-unit metric system, and International System of Units (SI)