Bar magnets and horseshoe magnets are two of the most common shapes of magnet. The magnetic field is shown by lines with arrows that point from north to south. You can tell how old some coins are ...

Of course there are new near field communication ... colorful magnetic cubes are placed on the tablet, [Andrea]’s app is able to differentiate between small, medium, and large magnets.

The other magnetic field going around the length of the doughnut is referred to as toroidal (green horizontal circle). The combination of these two fields creates a three ... Twisting the magnets can ...