Alternating Current

Having established how a sinusoidal emf is generated (sections 4.4.4 and 4.5), the unit now turns to analysing the alternating VOLTAGES and CURRENTS this emf produces once it actually drives a real circuit. This requires first defining how to meaningfully quantify a quantity that is constantly changing both its sign and its magnitude (mean and RMS values), then introducing phasors as a geometric bookkeeping tool for tracking phase relationships, and finally working systematically through purely resistive, purely inductive, purel …