Electromagnets... An electromagnet is a type of magnet in which the magnetic field is produced by the flow of electric current. The magnetic field disappears when the current is turned off. Electromagnets are widely used as components of other electrical devices, such as motors, generators, relays, loudspeakers, hard disks, MRI machines, scientific instruments, and magnetic separation equipment, as well as being employed as industrial lifting electromagnets for picking up and moving heavy iron objects like scrap iron. http://www.google.com/url?sa=t&rct=...yMHB4wO9iXatluEDGNqIFkg&bvm=bv.46471029,d.eWU
Rather than electromagnets, he's probably talking about neodymium magnets. They are very common and no, the only way to "turn them off" is with heat or an excessive number of blows with something like a heavy hammer (might take a few years of hammering, though.) Please Register or Log in to view the hidden image!