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 

An electron with kinetic energy $K _{1}$ enters between parallel plates of a capacitor at an angle $'\alpha'$ with the plates. It leaves the plates at angle $' \beta '$ with kinetic energy $K _{2}$. Then the ratio of kinetic energies $K _{1}: K _{2}$ will be ……. .

A sphere of radius $1\,cm$ has potential of $8000\,V$, then energy density near its surface will be

A $400\, pF$ capacitor is charged with a $100\, V$ battery. After disconnecting battery this capacitor is connected with another $400\, pF$ capacitor. Then find out energy loss.

A capacitor of capacitance $C$ is charged to potential difference $V_0$. Now this capacitor is connected to an ideal inductor. When $25\%$ of energy of capacitor is transferred to inductor then at that time what will be potential difference across capacitor