Alternating Current (AC): Definition, Formula, RMS, Power, Phasors, and Transformers Alternating current (AC) is an electric current in which both the magnitude and direction change periodically over time. This is fundamentally different from direct current (DC), where electric charge flows in only one direction. Most electrical power used in homes, offices, and industries worldwide is … Continue reading Alternating Current (AC): Definition, Formula, RMS, Power and Transformers