Question

A potential difference of $300$ volts is applied to a combination of $2.0\mu$F and $8.0\mu$F capacitors connected in series. The charge on the $2.0\mu$F capacitor is :

• A. $2.4\times {10}^{-4}coulomb$
• B. $4.8\times {10}^{-4}coulomb$
• C. $7.2\times {10}^{-4}coulomb$
• D. $9.6\times {10}^{-4}coulomb$

Answer 1

The correct option is B $4.8\times {10}^{-4}coulomb$

We know when capacitor are connected in series charge present on them must be equal.
In seris $\frac{1}{C_s}=\frac{1}{C_1}+\frac{1}{C_2}$
$\frac{1}{C_s}=\frac{1}{2}+\frac{1}{8}$
$\frac{1}{C_s}=\frac{5.}{8}$
$C_s=\frac{8}{5}\mu F$
$Q=CV$
$Q=\frac{8}{5}\times {10}^{-6}\times 300$
$Q=4.8\times {10}^{-4}C.$