$12$ positive charges of magnitude $q$ are placed on a circle of radius $R$ in a manner that they are equally spaced. A charge $Q$ is placed at the centre, if one of the charges $q$ is removed, then the force on $Q$ is
zero
$\frac{q Q}{4 \pi \varepsilon_0 R^2}$ away from the position of the removed charge
$\frac{11 q Q}{4 \pi \varepsilon_0 R^2}$ away from the position of the removed charge
$\frac{q Q}{4 \pi \varepsilon_0 R^2}$ towards the position of the removed charge
Two spherical conductors $B$ and $C$ having equal radii and carrying equal charges in them repel each other with a force $F$ when kept apart at some distance. A third spherical conductor having same radius as that of $B$ but uncharged is brought in contact with $B$, then brought in contact with $C$ and finally removed away from both. The new force of repulsion between $B$ and $C$ is
Why Coulombian force is called two body force ?
Three point charges are placed at the corners of an equilateral triangle. Assuming only electrostatic forces are acting
Two small spheres each having the charge $ + Q$ are suspended by insulating threads of length $L$ from a hook. This arrangement is taken in space where there is no gravitational effect, then the angle between the two suspensions and the tension in each will be
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