A sphere of radius R and charge Q is placed inside an imaginary sphere of radius `2R` whose centre coincides with the given sphere. The flux related to imaginary sphere is:

If a charge q is placed at the centre of imaginary sphere of radius r then the N.E.I. at a point on such a sphere is

A hollow sphere of radius 2R is charged to V volts and another smaller sphere of radius R is charged to V/2 volts. Now the smaller sphere is placed inside the bigger sphere without changing the net charge on each sphere. The potential difference between the two spheres would be

A hollow sphere of radius 2R is charged to V volts and another smaller sphere of radius R is charged to V/2 volts. Now the smaller sphere is placed inside the bigger sphere without changing the net charge on each sphere. The potential difference between the two spheres would be

A solid metall sphere of radius R has a charge + 2Q. A hollow spherical shell of radius 3R placed concentric with the sphere has charge - Q. Calculate the potential difference between the spheres.

A solid metall sphere of radius R has a charge + 2Q. A hollow spherical shell of radius 3R placed concentric with the sphere has charge - Q. Calculate the potential difference between the spheres.