The ratio of electric potentials at the point $E$ to that at the point $F$ is

If the electric potential of the inner shell of radius $a$ is $10\,V$ and that of the outer shell of radius $2a$ is $5\,V$,then the potential at the centre will be.....$V$

$A$ hollow charged metal sphere has radius $R$. If the potential difference between its surface and a point at a distance $5R$ from the centre is $V$,then the magnitude of the electric field intensity at a distance $5R$ from the centre of the sphere is:

Two conducting spheres of radii $r_1$ and $r_2$ have the same electric field intensity near their surfaces. The ratio of their electric potentials is

As shown in the figure,on bringing a charge $Q$ from point $A$ to $B$ and from $B$ to $C$,the work done is $2 \, J$ and $-3 \, J$ respectively. The work done to bring the charge from $C$ to $A$ is (in $, J$)

Calculate the work done in taking a charge $q_0 = -2 \times 10^{-9} \, C$ from point $A$ to point $B$ via point $C$,as shown in the diagram. The source charge $q = 8 \, mC$ is located at the origin $O$. (in $, J$)