Question

In the circuit shown in figure reading of voltmeter is $V_1$ when only $S_1$ is closed, reading of voltmeter is $V_2$ when only $S_2$ is closed and reading of voltmeter is $V_3$ when both $S_1$ and $S_2$ are closed. Then

• A. $V_2>V_1>V_3$
• B. $V_1>V_3>V_2$
• C. $V_3>V_1>V_2$
• D. $V_1>V_2>V_3$

Answer 1

The correct option is A $V_2>V_1>V_3$

In series: Potential difference $\propto R$

When only $S_1$ is closed $V_1=\frac{3}{4}E=0.75E$

When only $S_2$ is closed $V_2=\frac{6}{7}E=0.86E$

and when both $S_1$ and $S_2$ are closed combined resistance of $6R$ and $3R$ is $2R$

$\therefore V_3=\left(\frac{2}{3}\right)E=0.67$

$E\Rightarrow V_2>V_1>V_3$