http://web.mit.edu/8.02t/www/802TEAL3D/teal_tour.htm

Magnetostatics:
found this fantastic graphics for An animation of the magnetic field and forces generated by two parallel wires is visualized when the current in the wires run in opposite directions. When the current is turned on, the resulting magnet field pressure between the wires pushes them apart.
[img]http://web.mit.edu/8.02t/www/802TEAL3D/pirelli_images/Series_200.jpg[/img]