6  AC VOLTAGE APPLIED TO A SERIES  LCR CIRCUIT
Figure 7 10 shows a series LCR circuit connected to an ac source e As
usual, we take the voltage of the source to be v = vm sin wt If q is the charge on the capacitor and i the
current, at time t, we have, from Kirchhoff’s loop
rule:
dd
i
q
L
i R
v
t
C
+
+
=
(7