Question

In figure, battery B supplies 12 V. Find the charge on each capacitor when only switch $S_1$ is closed :

Answer 1

$C_{13}=\frac{1\times 3}{1+3}=\frac{3}{4}\mu F$

$C_{24}=\frac{2\times 4}{2+4}=\frac{4}{3}\mu F$

$V_{C_1{C}_3}=V_{C_2{C}_4}=12V$

$\therefore q_1=q_3=\left(C_{13}\right)\left(V_{C_1{C}_3}\right)=\frac{3}{4}\times 12=9\mu C$

$q_2=q_4=\left(C_{24}\right)\left(V_{C_2{C}_4}\right)=\frac{4}{3}\times 12=16\mu C$