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 $4 \;\mu\, F$ capacitor is charged by a $200\; V$ supply. It is then disconnected from the supply, and is connected to another uncharged $2 \;\mu\, F$ capacitor. How much electrostatic energy of the first capacitor is lost in the form of heat and electromagnetic radiation?

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.

A condenser of capacity $50\,\mu F$ is charged to $10\;volts$. Its energy is equal to

A $2\,\mu F$ capacitor is charged to $100$ $volt$ and then its plates are connected by a conducting wire. The heat produced is........$J$

A $12\,pF$ capacitor is connected to a $50\,V$ battery. How much electrostatic energy is stored in the capacitor