Q.
For the circuit shown, which of the following statements is true
A) With $S_{1}$ closed, $V_{1} = 15\ V,\ V_{2} = 20\ V$
B) With $S_{3}$ closed $V_{1} = V_{2} = 25V$
C) With $S_{1}$ and $S_{2}$ closed $V_{1} = V_{2} = 0$
D) With $S_{1}$ and $S_{3}$ closed, $V_{1} = 30V,V_{2} = 20V$
Explanation
(d) Charges on capacitors are $Q_{1} = 30 \times 2 = 60pC$ and $Q_{2} = 20 \times 3 = 60pC$ or $Q_{1} = Q_{2} = Q$ (say)
The situation is similar as the two capacitors in series are first charged with a battery of emf $50\ V$ and then disconnected
$\therefore$ when $S_{3}$ is closed $V_{1} = 30V$ and $V_{2} = 20V$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.