7.6 AC VOLTAGE APPLIED TO A SERIES LCR CIRCUIT

. AC VOLTAGE APPLIED TO A SERIES LCR CIRCUIT Figure . shows a series LCR circuit connected to an ac source ε. As usual, we take the voltage of the source to be v = vm sin ωt. If q is the charge on the capacitor and i the current, at time t, we have, from Kirchhoff’s loop rule: i L i R v ( . ) We want to determine the instantaneous current i and its phase relationship to the applied alternating voltage v. We shall solve this problem by two methods. First, we use the technique of phasors and in the second method, we solve Eq. ( . ) analytically to obtain the time– dependence of i. FIGURE . A series LCR circuit connected to an ac source.