When an additional charge of $2 \text{ C}$ is given to a capacitor,the energy stored in it increases by $21 \%$. The original charge of the capacitor is: (in $\text{ C}$)

An uncharged capacitor is connected to a battery. While charging the capacitor,how much is the energy lost,from the energy supplied by the battery (in $\%$)?

Two capacitors of capacitance $2 \ \mu F$ and $4 \ \mu F$ are connected in series. If a potential difference of $10 \ V$ is applied across this combination,what will be the ratio of the energy stored in these capacitors?

If the potential difference across a capacitor is increased from $5 \,V$ to $15 \,V$, then the ratio of final energy to initial energy stored in the capacitor is

$A$ capacitor is charged to $200\,V$. It has $0.1\,C$ of charge. When it is discharged,the energy released will be $J$.

If the charge on the capacitor is increased by $2 \text{ C}$, the energy stored in it increases by $21 \%$. The original charge on the capacitor is (in $\text{ C}$)