While the futuristic-sounding term "electromagnet" might conjure up images of extremely advanced, sophisticated technology that you would never expect to find lying around the house, manufacturers actually use electromagnets in a number of common home appliances. Unlike permanent magnets, electromagnets only display magnetic properties when electrical currents pass through them. Learn more about electromagnets and how different appliances utilise them.
If it were not for an electromagnet, each time you went to push down the tab or handle on your toaster, the bread would disappointingly pop right back up untoasted. As Drexel University's Geometric and Intelligent Computing Laboratory notes, when you push down a toaster tab on a functioning toaster, a piece of material wedges itself in between two electrical prongs, thereby completing a circuit. The resulting electrical current, in addition to producing heat, activates a small electromagnet. This electromagnet attracts a metallic section on the back of the tab, holding it, and the wire bread-clamps that hold the bread, in place. Once the toaster heats the bread for the time you set it for, it will disrupt the electrical current and deactivate the electromagnet, allowing the tab and clamps to pop back up.
Many computer printers rely on electromagnets to power their motors, which in turn power the printer's moving parts. As Solarbotics notes, these motors are known as stepper motors, and many other common electronics, such as fax machines and hard disk drives, also make use of them. A single stepper motor contains several stationary electromagnets known collectively as the stator, which surrounds a rotating, permanent magnet, known as the rotor. According to Images Scientific Instruments, to generate power, the motor conducts an electrical current into only one electromagnet at a time. As each electromagnet activates, it pulls the rotor towards it.
Unlike the above types of home appliances, microwave ovens do not utilise small electromagnets for momentarily attracting sections of metal. Instead, the entire microwave oven unit itself acts like a giant electromagnet to create a controlled zone of electromagnetism inside of its cooking chamber. As the University of Colorado Department of Physics notes, microwave ovens generate electromagnetic waves known as microwaves, which cause water molecules to move or vibrate. As the moving water molecules rub up against other molecules in the food or drink you are heating, they produce friction. This friction in turn generates heat and warms your items.