Two charged spherical conductors of radius $R_{1}$ and $\mathrm{R}_{2}$ are connected by a wire. Then the ratio of surface charge densities of the spheres $\left(\sigma_{1} / \sigma_{2}\right)$ is :
$\frac{\mathrm{R}_{1}}{\mathrm{R}_{2}}$
$\frac{R_{2}}{R_{1}}$
$\sqrt{\left(\frac{\mathrm{R}_{1}}{\mathrm{R}_{2}}\right)}$
$\frac{\mathrm{R}_{1}^{2}}{\mathrm{R}_{2}^{2}}$
A hollow conducting sphere is placed in an electric field produced by a point charge placed at $P$ as shown in figure. Let ${V_A},{V_B},{V_C}$ be the potentials at points $A,B$ and $C$ respectively. Then
The dielectric strength of air at $NTP$ is $3 \times {10^6}\,V/m$ then the maximum charge that can be given to a spherical conductor of radius $3\, m$ is
A spherical portion has been removed from a solid sphere having a charge distributed uniformly in its volume in the figure. The electric field inside the emptied space is
Obtain the relation between electric field and electric potential.
Write important results regarding electrostatic of conductors.