Question

In the figure, if the potential at point $P$ is $100\text{V}$, what is the potential at point $Q?$

• A. $-10\text{V}$
• B. $10\text{V}$
• C. $-20\text{V}$
• D. $20\text{V}$

Answer 1

The correct option is A $-10\text{V}$


Current through the circuit,

$I=\frac{150-50}{2+3}=20\text{A}$

From KVL, on going from point $P$ to $Q$ in anticlockwise direction,

$V_P-50-20\times 3=V_Q$

$\Rightarrow V_Q=V_P-110=100-110=-10\text{V}$