Assume that steady-state conditions exist in the circuit shown in Figure P4.27 for $t<0$ and that $V_1=15 \mathrm{~V}, R_1=100 \Omega, R_2=1.2 \mathrm{k} \Omega, R_3=400 \Omega, C=4.0 \mu \mathrm{~F}$. Determine the current $i_C$ through the capacitor at $t=0^{+}$, just after the switch is closed.
(FIGURE CAN'T COPY)
Figure P4.27