A parallel plate capacitor of capacity ${C_0}$ is charged to a potential ${V_0}$

$(i)$ The energy stored in the capacitor when the battery is disconnected and the separation is doubled ${E_1}$

$(ii)$ The energy stored in the capacitor when the charging battery is kept connected and the separation between the capacitor plates is doubled is ${E_2}.$

Then ${E_1}/{E_2}$ value is

A battery does $200 \,J$ of work in charging a capacitor. The energy stored in the capacitor is ……… $J$

Three plates $A, B$ and $C$ each of area $0.1 \ m^2$ are separated by $0.885\  mm$ from each other as shown in the figure. $A$ $10$ $V$ battery is used to charge the system. The energy stored in the system is

The work done in placing a charge of $8 \times {10^{ – 18}}$ coulomb on a condenser of capacity $100\, micro-farad$ is

In a uniform electric field, a cube of side $1\ cm$ is placed. The total energy stored in the cube is $8.85\ \mu J.$ The electric field is parallel to four of the faces of the cube. The electric flux through any one of the remaining two faces is.