If the distance between the plates of a capacitor having capacity $C$ and charge $Q$ is doubled then work done will be
$\frac{{{Q^2}}}{{4C}}$
$\frac{{{Q^2}}}{{2C}}$
$\frac{{{Q^2}}}{{C}}$
$\frac{{{2Q^2}}}{{C}}$
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
A charg $Q$ is divided into two parts $q$ and $Q-q$ and separated by a distance $R$ . The force of repulsion between them will be maximum when
The work done in placing a charge of $8 \times 10^{-18}$ coulomb on a condenser of capacity $100\, micro-farad$ is
The value of electric potential at any point due to any electric dipole is
A particle of charge $Q$ and mass $m$ travels through a potential difference $V$ from rest. The final momentum of the particle is