Two equally charged, identical metal spheres $A$ and $B$ repel each other with a force '$F$'. The spheres are kept fixed with a distance '$r$' between them. A third identical, but uncharged sphere $C$ is brought in contact with $A$ and then placed at the mid-point of the line joining $A$ and $B$. The magnitude of the net electric force on $C$ is

Two spheres $A$ and $B$ of radius $4\,cm$ and $6\,cm$ are given charges of $80\,\mu c$ and $40\,\mu c$ respectively. If they are connected by a fine wire, the amount of charge flowing from one to the other is

What is the net force on a $Cl^{-}$ placed at the centre of the bcc structure of $CsCl$

In given diagram. Find distance of neutral point from particle of charge $e$ is......$cm$

The ratio of the forces between two small spheres with constant charge $(a)$ in air $(b)$ in a medium of dielectric constant $K$ is

A given charge is situated at a certain distance from an electric dipole in the end-on position experiences a force $F$. If the distance of the charge is doubled, the force acting on the charge will be