Applying KCL, determine current I_S in the electric circuit to make V_0 = 16 V in the network shown in Fig. 2.40.
Now applying Kirchhoff’s current law to nodes A and B we have
I_1=I_2+I_s (i)
and I_2+I_3=\frac{V_1}{4} (ii)
also voltage of node B = V_0 =16 V
Voltage across AC + voltage across AB = voltage at node B.
Solving eq (i), (ii), (iii), and (iv) we have
\mathrm{V}_1=12 \mathrm{~V} \quad \mathrm{I}_1=2 \mathrm{~A} \quad \mathrm{I}_2=1 \mathrm{~A} \quad \mathrm{I}_{\mathrm{S}}=\mathrm{I}_1-\mathrm{I}_2=2-1=1 \mathrm{~A}Therefore, I_{\mathrm{s}}=1 \mathrm{~A} \quad I_3=\frac{V_1}{4}-I_2=3-1=2 \mathrm{~A}