A parallel plate capacitor has a uniform electric field $E$ in the space between the plates. If the distance between the plates is $d$ and area of each plate is $A,$ the energy stored in the capacitor is 

Two capacitors of capacitances $C$ and $2\, C$ are charged to potential differences $V$ and $2\, V$, respectively. These are then connected in parallel in such a manner that the positive terminal of one is connected to the negative terminal of the other. The final energy of this configuration is$.....CV^2$

Effective capacitance of parallel combination of two capacitors $\mathrm{C}_{1}$ and $\mathrm{C}_{2}$ is $10\; \mu \mathrm{F}$. When these capacitors are individually connected to a voltage source of $1\; \mathrm{V},$ the energy stored in the capacitor $\mathrm{C}_{2}$ is $4$ times that of $\mathrm{C}_{1}$. If these capacitors are connected in series, their effective capacitance will be

Two insulated metallic spheres of $3\,\mu F$ and $5\,\mu F$ capacitances are charged to $300\, V$ and $500\,V$ respectively. The energy loss, when they are connected by a wire is

A capacitor of capacitance $\mathrm{C}$ and potential $\mathrm{V}$ has energy $E$. It is connected to another capacitor of capacitance $2 \mathrm{C}$ and potential $2 \mathrm{~V}$. Then the loss of energy is $\frac{x}{3} E$, where $\mathrm{x}$ is____________.

If the charge on a capacitor is increased by $2C$, the energy stored in it increases by $44 \%$. The original charge on the capacitor is (in $C$ )