$A$ capacitor of capacity $C$ has charge $Q$ and stored energy is $W$. If the charge is increased to $2Q$,the stored energy will be

Three plates $A, B, C$ each of area $50 \, cm^2$ have a separation of $3 \, mm$ between $A$ and $B$ and $3 \, mm$ between $B$ and $C$. The energy stored when the plates are fully charged is (as shown in the figure):

$A$ parallel plate capacitor having a plate separation of $2\, mm$ is charged by connecting it to a $300\, V$ supply. The energy density is.....$J/m^3$

The energy required to charge a capacitor of $5\,\mu F$ by connecting a $d.c.$ source of $20\,kV$ is......$kJ$.

$A$ capacitor has two circular plates,each of radius $8\,cm$,separated by a distance of $1\,mm$. $A$ dielectric slab (dielectric constant $K = 6$) is inserted between the plates. Calculate the energy stored in the capacitor when it is connected to a $150\,V$ potential difference.

If potential difference across a capacitor is changed from $15 \ V$ to $30 \ V,$ work done is $W.$ The work done,when potential difference is changed from $30 \ V$ to $60 \ V,$ will be $.......W$