an alternating current that constitutes a sinusoidal function of time in the form i = I_m sin (ωt + Φ), where i is the instantaneous value of the current, I_m is the current’s amplitude, ω is the angular frequency, and Φ is the initial phase angle. Inasmuch as a sinusoidal function resembles its derivative, in all parts of a linear circuit carrying a sinusoidal current the voltages, currents, and induced emf’s are also sinusoidal. The use of sinusoidal currents in technology simplifies electrical devices and circuits, as well as design calculations. [23–1297–]