Answer to Question #50819 in Electricity and Magnetism for Saktesh Mahapatra

A)A sphere of radius R carries a charge of volume charge density p = cr, where c is a constant and r denotes the distance from the centre of the sphere. Calculate the total charge enclosed by the sphere and the electric field at points lying inside and outside the sphere. B) A dielectric object is placed in an electric field. The object becomes polarised and a large number of atomic /molecular dipoles in the object align in the direction of the applied electric field. Derive an expression for the electric field produced by this polarised dielectric at a point outside the dielectric object. C)Determine the magnitude of the pointing vector and the energy per unit time delivered to a wire of length L and cross-section A when electric current I flows in it.