Question

In the circuit shown in Fig, resistors $X$ and $Y$ each with resistance $R$, are connected to 6 V battery of negligible internal resistance. A voltmeter, also of resistance $R$, is connected across $Y$. What is the reading of the voltmeter?

• A. Zero
• B. Between zero and 3V
• C. 3 V
• D. Between 3 V and 6 V

Answer 1

The correct option is B Between zero and 3V

The given circuit can be converted into equivalent circuit as shown in figure.
The total current through the circuit is given by
$I=\frac{6}{\frac{3}{2}R}=\frac{4}{R}A$
The current through the voltmeter is half of this current i.e. $\frac{I}{2}$ or $\frac{2}{R}$ A. Hence, the reading of the voltmeter is $\frac{2}{R}\left(R\right)$ or 2 V i.e. in between 0V and 3V.