An electric dipole is placed in uniform electric field in an unstable equilibrium position. Now the dipole is rotated in this field. The graph which best represents variation of its potential energy is given by,

To reduce the capacity of a parallel plate capacitor, separation between the plates is

How do you arrange four equal capacitors of $4 \mu \mathrm{F}$ to get effective capacitance $3 \mu \mathrm{F}\text{?}$

Two parallel plate capacitors of capacitances $C$ and $2C$ are connected in parallel and charged to a potential difference $V.$ The battery is then disconnected and the region between the plates of the capacitor $C$ is completely filled with a material of dielectric constant $K\mathit{.}$ The potential difference across the capacitors now becomes -

When dielectric is inserted in the space between plates of a capacitor, then

A parallel plate capacitor has a capacity $C$. If a medium of dielectric constant $k$ is introduced between plates, the capacity of capacitor becomes