Three concentric spherical shells have radii $a, b$ and $c (a < b < c)$ and have surface charge densities $\sigma ,-\;\sigma $ and $\;\sigma \;$ respectively. If $V_A,V_B$ and $V_C$ denote the potentials of the three shells, then, for $c = a +b,$ we have
$V_C=V_B \ne V_A$
$V_C \ne V_B \ne V_A$
$V_C=V_B=V_A$
$V_C=V_A \ne VB$
A cube of side $b$ has a charge $q$ at each of its vertices. Determine the potential and electric field due to this charge array at the centre of the cube.
Draw a graph of $V \to r$ for spherical shell.
Charges are placed on the vertices of a square as shown. Let $E$ be the electric field and $V$ the potential at the centre. If the charges on $A$ and $B$ are interchanged with those on $D$ and $C$ respectively, then
Four charges $2C, -3C, -4C$ and $5C$ respectively are placed at all the corners of a square. Which of the following statements is true for the point of intersection of the diagonals ?
A small conducting sphere of radius $r$ is lying concentrically inside a bigger hollow conducting sphere of radius $R.$ The bigger and smaller spheres are charged with $Q$ and $q (Q > q)$ and are insulated from each other. The potential difference between the spheres will be