Question

the charge on capacitors $C_{1}$ and $C_{4}$ are

• A. $4 \times 10^{-3}\, C, 12 \times 10^{-3} \, C$
• B. $6 \times 10^{-3}\, C, 12 \times 10^{-3} \, C$
• C. $2 \times 10^{-3}\, C, 4 \times 10^{-3} \, C$
• D. $3 \times 10^{-3}\, C, 2 \times 10^{-3} \, C$

Answer 1

Answer: (A)

Charge on each capacitor, $C_{1}, C_{2}, C_{3}$ is same $= q$ Let charge on $C_{4}$ be $q$'
$\therefore \frac{q}{C_{1}}+\frac{q}{C_{2}}+\frac{q}{C_{3}}=600 $
or $q\left[\frac{1}{C_{1}}+\frac{1}{C_{2}}+\frac{1}{C_{3}}\right]=600$
or $\frac{q}{C_{s}}=600$
$\therefore q=600 C_{s}=600\times\frac{20}{3} \mu C$
$4000\times10^{-6}C=4\times10^{-3}C$
Also $\frac{q'}{C_{4}}=600$
or $q'=C_{4}\times600 \mu C$
$=200\times600\, \mu C$
$=12\times10^{-3} C$