Question

Two condensers, one of capacity $2C$ and the other of capacity $\frac{C}{2}$, are connected to a $V$-volt battery, as shown,

The work done by battery in charging fully both the condensers is :-

• A. $\frac{1}{2}C{V}^2$
• B. $2C{V}^2$
• C. $\frac{5}{2}C{V}^2$
• D. $\frac{3}{2}C{V}^2$

Answer 1

Answer: (C)

$C_{eq}=2C+\frac{C}{2}=\frac{5C}{2}$
$q_{\text{Battery }}=C_{eq}V=\frac{5CV}{2}$
$W_{\text{Battery }}=\left(q_{\text{Battery }}\right)V=\frac{5C{V}^2}{2}$