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

Inside a hollow charged spherical conductor, the potential

An empty thick conducting shell of inner radius $a$ and outer radius $b$ is shown in figure.If it is observed that the inner face of the shell carries a uniform charge density $-\sigma$ and the surface carries a uniform charge density $ '\sigma '$

If another point charge $q_B$ is also placed at a distance $c ( > b) $ the center of shell, then choose the correct statements 

Three concentric metallic spherical shells of radii $R, 2R, 3R$, are given charges $Q_1, Q_2, Q_3$, respectively. It is found that the surface charge densities on the outer surfaces of the shells are equal. Then, the ratio of the charges given to the shells, $Q_1 : Q_2 : Q_3$ is

The magnitude of electric field on the surface of a uniformly charged metalic spherical shell is $E$. If a hole is made in it using a insulating device, then the magnitude of electric field in the hole will be

Four metal conductors having different shapes

$1.$  A sphere     $2.$  Cylindrical

$3.$  Pear            $4.$  Lightning conductor

are mounted on insulating stands and charged. The one which is best suited to retain the charges for a longer time is