i don't understand this. if i have a charge inside a hollow conductor of say +Q and a charge of -Q on the conductor it doesn't matter how close the interior charge is to the wall of the conductor ( but not touching ) the field at all points on the surface of the conductor will be zero? doesn't make sense to me. i'm imagining that if i put the +Q charge close to the interior wall of the conductor there will be a build up of negative charge next to it on the interior wall inside the conductor. This will in effect draw positive charge to that clump of negative charge on the exterior wall of the inside of the conductor and cause a stronger e field there? But ofcourse gauss's law says that the e field will be zero every where on the outside?