Two hollow conducting spheres of radii $R_1$ and $R_2$ $\left(R_1\gg R_2\right)$ have equal charges. The potential would be:

A capacitor of capacitance $\mathrm{C}=900 \mathrm{pF}$ is charged fully by $100 \mathrm{V}$ battery $B$ as shown in figure (a). Then it is disconnected from the battery and connected to another uncharged capacitor of capacitance $C=900 \mathrm{pF}$ as shown in figure (b). The electrostatic energy stored by the system (b) is

Two point charges $-q$ and $+q$ are placed at a distance of $L$, as shown in the figure.

The magnitude of electric field intensity at a distance $R\left(R\gg L\right)$ varies as

A dipole is placed in an electric field as shown. In which direction will it move?

The equivalent capacitance of the combination shown in the figure is: