*12.22 Repeat Problem 12.21, but assume that the switch had been open for a long time and then closed at $t = 0$. Set the dc source at 12 mV and the element values at $R_0 = 5 \Omega$, $R_1 = 10 \Omega$, $R_2 = 20 \Omega$, $L = 2 \text{H}$, and $C = 0.4 \text{F}$.
Figure P12.21: Circuit for Problems 12.21 and 12.22.