Question

A potential difference of 300 V 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 x 10^-4 C
• B. 4.8 x 10^-4 C
• C. $7.2 \times 10^{-4}C$
• D. $9.6 \times 10^{-4}C$

Answer 1

Answer: (B)

V = 300V, $C_1 = 2.0\mu F, C_2 = 8.0\mu F$
Not Capacitance, $\frac1C_s=\frac1C_1+\frac1C_2$
$\Rightarrow C_8=\frac{ C_1C_2}{C_1+C_2}$
$\Rightarrow C_s=\frac{2 \times 8}{2+8}=\frac{16}{10}=1.6 \mu F.$
Now total charge,
$Q=V_s \times C_s = 300 \times 1.6 \times 10^{-6}=4.8 \times 10^{-4} C.$
$\because$ In series charge is same on capacitors
$\Rightarrow $ Charge on $2\mu F$ capacitor is $4.8 X 10^{-4}C$