Answer
(a) No net charge is enclosed. There is no net flux through the bottom surface, the flux into the left-hand side is cancelled by the flux out of the right-hand side.
(b) Net positive charge is enclosed since the flux is outward on all surface.
(c) Net negative charge is enclosed since the flux is inward on all surface.
Work Step by Step
(a) No net charge is enclosed. There is no net flux through the bottom surface, the flux into the left-hand side is cancelled by the flux out of the right-hand side.
(b) Net positive charge is enclosed since the flux is outward on all surface.
(c) Net negative charge is enclosed since the flux is inward on all surface.
