When you use electricity to iron your clothes or toast your bread, two things happen. Electricity makes a strong push in a wire, and the wire pushes back!
Electricity makes the iron and the toaster heat up. The electricity travels into and out of these machines on wire pathways. Most of the pathways conduct electricity easily, so the electrons are free to move.
But inside the iron and the toaster, part of the pathway is made of a different kind of wire. This wire is made from a kind of metal in which the electrons don’t move very easily. Often the wire is very thin, and sometimes it is wound into a long, tight coil. Instead of conducting electricity easily, this part of the pathway resists the current. The electrons have to push hard to move through this wire.
The pushing electrons make the molecules in the wire speed up and bump into one another. The harder they bump and push, the hotter the wire gets. In a few minutes, the bumping and pushing make the wire hot. And the heat presses clothes or toasts bread.
In irons and toasters, resistance is a good thing. But in many machines, resistance is a waste of electricity. So scientists are always working to create materials that can conduct electricity without resistance. These materials are called superconductors. Someday, people may travel on high-speed trains that float on superconducting magnets. Test models of these trains have already reached speeds of more than 400 kilometres per hour.
Picture Credit : Google
