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

Electric field at a place is $\overrightarrow E  = {E_0}\widehat i\,\,V/m$. A particle of charge $+q_0$ moves from point $A$  to $B$ along a circular path find work done in this motion by electric field :-

Half of the space between parallel plate capacitor is filled with a medium of dielectric constant $K$ parallel to the plates . If initially the capacity is $C$, then the new capacity will be

A parallel plate capacitor has a uniform electric field $E$ in the space between the plates. If the distance between the plates is $d$ and area of each plate is $A$ , the energy stored in the capacitor is

Consider a cube of uniform charge density $\rho$. The ratio of electrostatic potential at the centre of the cube to that at one of the corners of the cube is

The work done required to put the four charges together at the corners of a square of side $a$ , as shown in the figure is