In the following circuit, what is the voltage across PQ? | Physics - Electric Circuits (Kirchhoff's Laws) | SolveeIt

In the following circuit, what is the voltage across PQ?

$\frac{5}{3}V$

$\frac{10}{3}V$

$\frac{11}{3}V$

$\frac{8}{3}V$

Answer

$\frac{10}{3}\text{ V}$

Explanation

Let the voltage across PQ be $V$ . In the top branch, the current is

I_1 = \frac{4 - V}{1}

and in the bottom branch, the current is

I_2 = \frac{2 - V}{2}.

Since the branches are connected in parallel, by Kirchhoff's Current Law, the net current is zero:

I_1 + I_2 = 0 \implies (4 - V) + \frac{2 - V}{2} = 0.

Multiplying through by 2 to eliminate the fraction, we get:

2(4 - V) + (2 - V) = 0 \implies 8 - 2V + 2 - V = 0 \implies 10 - 3V = 0.

Solving,

V = \frac{10}{3}\text{ V}.

Question: In the following circuit, what is the voltage across PQ? ...