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 20)
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