(a) Explain, using suitable diagrams, the differnce in the behaviour of a (i) conductor and (ii) dielectric in the presence of an external electric field. Define the terms polarization of a dielectric and write its relation with susceptibility.
(b) A thin metallic spherical shell of radius R carries
placed at its centre C and an other charge +2Q is placed outside the shell at a distance x from the centre as shown in the figure. Find (i) the force on the charge at the centre of shell and at the point A, (ii) the electic flux through the shell.