Question

A 4 $\mu$F capacitor is given 20 $\mu$C charge and is connected with an uncharged capacitor of capacitance 2 $\mu$F as shown in figure. When switch S is closed –

• A. Charged flown through the battery is $\frac{40}{3}\mu C$
• B. Charge flown through the battery is $\frac{20}{3}\mu C$
• C. Work done by the battery is $\frac{200}{3}\mu J$
• D. Work done by the battery is $\frac{100}{3}\mu J$

Answer 1

Answer: (B), (C)

The correct options are
B

Charge flown through the battery is $\frac{20}{3}\mu C$

C

Work done by the battery is $\frac{200}{3}\mu J$

$\frac{20+x}{4}+\frac{x}{2}-10=0$

$\frac{3x}{4}=5;x=\frac{20}{3}\mu C$

Work done by battery $=x\times 10=\frac{200}{3}\mu C$