Resistors work by converting electrical energy That's why it's coiled: a coil packs more length (and light) into the same space. The amount of light a filament produces is directly related to how long it is: the longer the filament, the more light it gives off. Photo: A closeup of the coiled tungsten filament in an incandescent lamp, which makes light by making a great deal of heat. Lower the current in a loudspeaker circuit is a way of turning down How much current flows using a dial to increase the resistance and In an electric orĮlectronic circuit, we can use devices called Struggle for the electricity to get through). Them easily) while insulators have a much higher resistance (it's a real So conductors have a low resistance (electricity flows through How much resistance they put up when an electric currentįlows through them. While the poor carriers are known as insulators.Ĭonductors and insulators are often better described by talking about The good carriers of electricity are called conductors, In school we learn that some materials carry electricity well, othersīadly. Does a heating element need a high or a low resistance?.We still love the romance of fire, even if we prefer the convenience of electricity! At the top, there's a pretty unconvincing pile of plastic coal that serves no useful purpose, other than to remind us we're cave dwellers at heart. You can see the elements right in the middle of the picture running horizontally and glowing red hot. This one has three electric heating elements ("bars") mounted in white ceramic behind a silver-colored safety grid. Photo: A typical electric fire standing on a stone hearth. Heating elements give us the power ofįire with the convenience of electricity. They're the "fire" inside such things as electric heaters, Wouldn't it be great if fire were as easy to control asĮlectricity, so you could switch it on and off at a moment's notice?Įlements. Other times fire breaks out when you leastĮxpect it, threatening lives, buildings, and everything you holdĭear. Locomotives have to be fired up several hours before they need to Sometimes it takes ages to get a fire going: coal-powered steam Plastics, smoke and flames might seem positively prehistoric.īut all four of those inventions-and dozens of others besides-rely on fire inįire is nothing less than brilliant, but it's not all that convenient. Space rockets, steel skyscrapers, and synthetic Last updated: March 25, 2022.įire was one of humankind's earliest and greatest discoveries-something over one million years ago.
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