Question

Three resistances are joined together to form a letter $Y$, as shown in figure. If the potentials of the terminals $A,B$ and $C$ are $6\text{V},3\text{V}$ and $2\text{V}$ respectively, then the potential of the point $O$ will be

• A. $4\text{V}$
• B. $3\text{V}$
• C. $2.5\text{V}$
• D. $0\text{V}$

Answer 1

The correct option is B $3\text{V}$

Let the voltage at $O$ be $V_0$.
By applying $KCL$ at $O$


$I_1+I_2+I_3=0$
$\Rightarrow \frac{6-V_0}{6}+\frac{3-V_0}{3}+\frac{2-V_0}{2}=0$
$\Rightarrow 6-V_0+2(3-V_0)+3(2-V_0)=0$
$\therefore V_0=3\text{V}$