Two equal point charges are fixed at $x = -a$ and $x = + \,a$ on the $x$-axis. Another point charge $Q$ is placed at the origin. The change in the electrical potential energy of $Q$ ehen it is displaced by a small distance $x$ along the $x$ -axis is apporximately proportional to
$x$
$x^2$
$x^3$
$1/x$
A charge $Q$ is distributed over two concentric conducting thin spherical shells radii $r$ and $R$ $( R > r ) .$ If the surface charge densities on the two shells are equal, the electric potential at the common centre is
Three identical dipoles are arranged as shown below. What will be the net electric field at $M$
Two identical charged spherical drops each of capacitance $C$ merge to form a single drop. The resultant capacitance
Electrostatic field of a long uniformly charged wire varies with distance $(r)$ according to relation
In the figure a potential of $+ 1200\, V$ is given to point $A$ and point $B$ is earthed, what is the potential at the point $P$....$V$