Hi colleagues, I need your help to figure out some subtle theory problmes I have about this topic. I was thinking about a system composed by a conductive sphere (not grounded) under the effect of a pont charge placed near the sphere. As I know we need two image charges to satisfy the boundary conditions of the system, precisely a constant potential over the sphere surface and its value going to zero when distance from the system approaches infinity. Actually we need two opposite image charges but equals in modulus, one of these placed in the center of the sphere. This is convincing because the actual flux round the sphere is zero as it should be for a conductive finte object. But when it comes the sphere to be grounded, the problem is solved placing just one image charge inside the sphere to satisfy the condition of having potential equals zero throughout the sphere surface. This setting however does not lead to nullify the flux valuated on the sphere surface, as I think it should be equal to zero. How is this explained? Can anyone find flaws in my reasoning? Is there something I am missing? Really appreciate any help! Have a good day!