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
${\varepsilon _0}EAd$
$\;\frac{1}{2}{\varepsilon _0}\frac{{{E^2}}}{{Ad}}$
$\;\frac{1}{2}\;{\varepsilon _0}{E^2}Ad$
$\;{\varepsilon _0}\frac{{{E^2}}}{{Ad}}$
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
A $60\; pF$ capacitor is fully charged by a $20\; \mathrm{V}$ supply. It is then disconnected from the supply and is connected to another uncharged $60 \;pF$ capactior is parallel. The electrostatic energy that is lost in this process by the time the charge is redistributed between them is (in $nJ$)
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.....$J/m^3$
A $4\, \,\mu F$ condenser is charged to $400\, V$ and then its plates are joined through a resistance. The heat produced in the resistance is.......$J$
A parallel plate capacitor has plate area $A$ and separation $d$. It is charged to a potential difference $V_o$. The charging battery is disconnected and the plates are pulled apart to three times the initial separation. The work required to separate the plates is