A charge q is distributed over two concentric hollow spheres of raddii r and R such that the surface densities are equal. Find the potential at the common centre.

A hollow metallic sphere of radius 10 cm is charged, such that potential of its surface is 70 V. The potential at the centre of the sphere would be

A hollow metal sphere of radius 5 cm is charged, such that the potential on its surfae is 10 V. The potential at the centre of the sphere is

A charge q is distributed unifromly on x ring of radius r. A sphere of equal radius r is centred at the circumference of the ring . Find the flux of the electric field through the surface of the sphere.

Two concentric hollow spheres are arranged as shown in the figure. If a charge +Q is given to the outer sphere, find charge induced on the inner sphere.

A solid conducting sphere having a charge Q is surrounded by an uncharged concentric hollow spherical shell. Let the potential difference between the surface of the solid sphere and that of the outer surface of the hollow shell be v. If the shell is now given a charge of -3 Q, the new potential difference between the same two surfaces is _____.

Fill ups A point charge is placed at the centre of a hollow conducting sphere of internal radius 'r' and outer radius '2r'. The ratio of the surface charge density of the inner surface to that the outer surface will be…………….. .

A charge Q coulomb is uniformly distributed over a sphere volume of radius R metres. Obtain an expression for the energy of the system.

A non-conducting solid sphere of radius R is uniformly charged. The magnitude of the electric field due to the sphere at a distance r form its centre

Three concentric spherical metal sheels A,B and C of radii a,b and c a'< 'b'<'c have surface charge densities +sigma, -sigma and +sigma respectively. Find the potentials of three sheels A,B and C.

A solid metal sphere of radius r has charge +Q. This charge is one the surface of the sphere but it may be considered to be a point charge at its centre. The sphere has radius 36 cm. Determine, for this sphere the capaciance the charge requried to raise the potential of the sphere form zero to 7.0 xx 10^5V .