A solid conductor sphere of radius ‘a’ has a positive net charge 2Q as shown in Figure A. A conductor spherical shell of inner radius ‘b’ and external radius ‘c’ has the same center with the solid sphere and has a net charge -Q. Using Gauss' Law determine the electric field in the regions denoted as (1), (2), (3) & (4) in the Figure B, and the charge distribution over the shell when all the system is in electrostatic equilibrium.