Question

In a portion of some large electrical network, current in certain branches are known. The values of$V_A{V}_B$ and $V_C{V}_D$ are X and Y respectively. Where X and Y are:

• A. X = 29 V, Y = 26 V
• B. X = 58V, Y = 52 V
• C. X = -58 V, Y = -52 V
• D. X = -29 V, Y = -26 V

Answer 1

The correct option is B X = 58V, Y = 52 V

Using Kirchhoff's law of current,

$7=2+3+I_x⟹I_x=2A$

$⟹$ current of $2A$ is entering in a circuit.

Now, using Kirchhoff's law for point $A$ to $B$,

$⟹V_A-14-3-5-20-4-12-V_B=0$

$⟹V_A-V_B=58V$

Now, using Kirchhoff's law for point $C$ to $D$,

$V_C-9+8\left(2\right)-5-20-4-30-V_D=0$

$⟹V_C-V_D=52V$