Draw magnetic field (b field) line diagrams for the following. make sure the diagrams are large enough so the direction and shape of the magnetic field is very clear. include magnetic field lines that are far from their sources. a. a bar magnet (be sure to label the north and south pole). b. a horseshoe magnet (be sure to label the north and south pole). c. a long straight wire with an electric current in it (be sure to label the direction of the current).