Basics of Alternating Current Circuits

Until now, the analysis has been limited to electrical circuit networks with time-invariant sources, also known as DC sources. At this point, the focus of the circuit analysis will be shifted towards time-varying sources. In the electrical domain, the magnitude of a time-varying source varies between two preset levels with time. In this domain, a sinusoidal time-varying source is generally known as an AC (derived from the name, Alternating Current) source. Circuits, driven by AC sources (current or voltage), are known as AC circuits. The generation, transmission, and distribution of AC sources are more efficient than those of time-invariant sources. AC signals in any electrical circuit are also easy to analyze with diverse mathematical tools. The development of AC sources along with the formulation of associated mathematical theories has expanded the electrical power industries at an enormous rate in the whole world. This chapter presents all the fundamental concepts of AC sources along with some relevant circuit analysis.