Question

Two voltameters A and B both have resistance 2R shown

When a battery is connected between x and y, the voltmeter readings are $V_A$ and $V_B$ respectively. Then

• A. $V_A = V_B$
• B. $V_A > V_B$
• C. $V_A < V_B$
• D. Data insufficient

Answer 1

Answer: (A)

$V_A = V_B$

Answer 2

In the circuit, the two voltmeters (each of resistance $2R$) are connected in series with the resistor between terminals $x$ and $y$. Since they are identical parts of a single series branch, the same current $I$ flows through both, so the voltage drop across each is given by

$$V_A = I \cdot 2R,\quad V_B = I \cdot 2R.$$

Thus, clearly, $V_A = V_B$.