Animation 1

Animation 2

Add Compass


The above animations represent a typical bar magnet with a North and South pole. You may double click anywhere inside the animation to add a magnetic field line. You may also add a compass by clicking the “Add Compass” link.


Which animation correctly depicts a properly labeled magnet?


Instructor Resources

Reference: See Giancoli-PA: 20-1, Giancoli-SE: 27-1.
Answer: Animation 1. In this animation, there are two ways to determine whether the magnet is properly labeled. One involves double-clicking in the applet to add a magnetic field line. Magnetic field lines leave from North poles and enter South poles, and therefore this animation is correct. The second method involves a depiction of an actual in-class demonstration or lab experiment. By adding a compass, the animation depicts moving a compass around a permanent magnet. Since multiple compasses can be added, ask students what they think the relationship between the compass needles and the magnetic field lines will be. The compass needles should point tangent to the magnetic field lines. This can also be shown with one compass by dragging it to follow a field line.
Script Author: Mario Belloni