Two charged spherical conductors of radii $R_1$ and $R_2$ are connected by a wire. The ratio of surface charge densities of the spheres $\sigma _1/\sigma _2$ will be
$\frac{{{R_1}}}{{{R_2}}}$
$\frac{{{R_2}}}{{{R_1}}}$
$\sqrt {\left( {\frac{{{R_1}}}{{{R_2}}}} \right)} $
$\frac{{R_1^2}}{{R_2^2}}$
Two capacitors $C_1$ and $C_2 = 2\,C_1$ are connected in a circuit with a switch between them as shown in the figure. Initially the switch is open and $C_1$ holds charge $Q$. The switch is closed. At steady state, the charge on capacitors will be
In the given figure, three capacitors $C_1, C_2$ and $C_3$ are joined to a battery, with symbols having their usual meanings, the correct conditions will be
Two charges $ + 3.2\, \times \,{10^{ - 19}}\,C$ and $ - 3.2\, \times \,{10^{ - 19}}\,C$ kept $2.4\,\mathop A\limits^o $ apart forms a dipole. If it is kept in uniform electric field of intensity $4\, \times \,{10^{5\,}}\,volt/m$ then what will be its potential energy in stable equilibrium
A thin spherical conducting shell of radius $R$ has charge $q$. Another charge $Q$ is placed at the centre of the shell. The electrostatic potential at a point $P$ at a distance $R/2$ from the centre of the shell is
Figures below show regular hexagons, with charges at the vertices, In which of the following cases the electric field at the centre is not zero.