Question

In the following network potential at ${}^{\prime }{O}^{\prime }$

• A. 4 V
• B. 3 V
• C. 6 V
• D. 4.8 V

Answer 1

Answer: (D)

Let the potential at $O$ is $V_0$.
Application of Kirchhoff's first law at junction $O$ gives
$\frac{8-V_0}{2}=\frac{V_0-4}{4}+\frac{V_0-2}{2}$
$=\frac{V_0-4+2V_0-4}{4}$
$\frac{4\left(8-V_0\right)}{2}=V_0-4+2V_0-4$
$16-2V_0=3V_0-8$
$16+8=5V_0$
$V_0=\frac{24}{5}=4.8V$