Two non-conducting spheres of radii $R_1$ and $R_2$ and carrying uniform volume charge densities $+\rho$ and $-\rho$, respectively, are placed such that they partially overlap, as shown in the figure. At all points in the overlapping region: $Image$

$(A)$ the electrostatic field is zero

$(B)$ the electrostatic potential is constant

$(C)$ the electrostatic field is constant in magnitude

$(D)$ the electrostatic field has same direction

An electric charge ${10^{ - 3}}\,\mu \,C$ is placed at the origin $(0, 0)$ of $X -Y$ co-ordinate system. Two points $A$ and $B$ are situated at $\left( {\sqrt {2\,} \,,\,\,\sqrt 2 } \right)$  and $(2, 0)$ respectively. The potential difference between the points $A$ and $B$ will be......$volt$

A table tennis ball which has been covered with conducting paint is suspended by a silk thread so that it hang between two plates, out of which one is earthed and other is connected to a high voltage generator. This ball

Four point charges $-Q, -q, 2q$ and $2Q$ are placed, one at each comer of the square. The relation between $Q$ and $q$ for which the potential at the centre of the square is zero is

Two charges of magnitude $+ q$ and $-\,3q$ are placed $100\,cm$ apart. The distance from $+ q$ between the charges where the electrostatic potential is zero is.......$cm$

The give graph shown variation (with distance $r$ from centre) of