There's no point in this element being any other shape or size: it has to concentrate heat precisely underneath a cooking pan-and this is the most effective way to achieve that.Ī typical heating element is usually a coil, ribbon (straight or corrugated), or This is one continuous element, beginning at the blue dot and curving around in a maze shape until it reaches the red dot. Photo: The heating element concealed inside a ceramic cooktop. What we're talkingĪbout here is the essence of a heating element: a sturdy electricalĬomponent designed to throw out heat when a big electric current Instead of white hot, so it didn't blind us). Heat at a reasonable temperature (maybe when it glowed red hot Repeated heating and cooling) and we'd need it to give off lots of Robust material (one that didn't melt and lasted a long time through More powerful so we could really feel the heat. We'd need something like a scaled-up lamp filament-maybe 20–30 times But if you stand evenĪ meter or so away, the heat from something like a 100-watt lamp isĮlectric heater broadly along the same lines as an electric lamp? You if you touch it (don't be tempted to try). If you've ever gotĬlose to an incandescent lamp, you'll know it gets hot enough to burn In? Suddenly, we find our wasteful incandescent lamp is actually veryĮfficient, because it converts 95 percent of the energy we feed into
Now forget the light-what if the heat were the thing we were really interested Turned into heat and completely wasted (using anįluorescent lamp is far more efficient, because most of theĮlectricity the lamp consumes is converted into light with hardly any Aroundĩ5 percent of the energy a lamp like this uses is It glows white hot, very brightly-so it's really making light by making heat. When enough electricity flows through it, Inside the glass bulb, there's a very thin coil That's the basic idea behindīulb-shaped lights). Even a thin piece of wire will get hot if youįorce enough electricity through it. They get hot when electricity flows through them. 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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