Hello , firs of all I know that every magnet has two poles ad the field lines exit one pole and enter into the other , now if we take a bunch of magnets , for simplicity assume an infinitely long line of magnets each seperated by a distance , all of the magnets facing N-S N-S N-S , now do the field lines of the previous magnet exit and enter the poles of the same magnet or can the field lines say exit from the previous magnet's N pole and enter into the next magnets S pole? In other words if a magnets one pole is already attracted to a different magnet can the other pole field lines of the same magnet then go on to yet another magnet and so forth as long as each next magnet meets a new one for the field lines to go to ? Now my second question is what happens in a magnet sphere ? Now I know that the E field inside a conducting sphere with a surface charge is zero and I ahve heard that also f a sphere would be made out of magnetic material the B field inside would also be zero , but what would happen if I had half a sphere in other words a permanent magnet sphere jsut cut in half , so that each side has a N and a S pole , assuming the inner sides are the N or S poles , I then put these half sides together but leave a tiny gap so that they dont touch physically , what would happen ? the two sides would be repelled constantly right? Say I hold them together with screws (non conducting ones) what happens , do I have a B field inside ? and is the line of the tiny seperation a cusp ?