Question

In the circuit shown in the 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. $V_{3}>V_{2}>V_{1}$
• B. $V_{2}>V_{1}>V_{3}$
• C. $V_{3}>V_{1}>V_{2}$
• D. $V_{1}>V_{2}>V_{3}$

Answer 1

Answer: (B)

$V_{2}>V_{1}>V_{3}$
When $S_{1}$ closed

$V_{1}=\frac{3 R}{R + 3 R}E=\frac{3}{4}E$
When $S_{2}$ is closed

$V_{2}=\frac{6 R}{R + 6 R}E=\frac{6}{7}E$
When both $S_{1}$ and $S_{2}$ are closed

$V_{3}=\frac{2 R}{R + 2 R}E=\frac{2 E}{3}$
$\therefore \, \, \, V_{2}>V_{1}>V_{3}$