Electricity and transport

How does a toaster work?

Appliances that heat up, such as a toaster, all work on the same idea. They change electrical energy to heat energy.

The devices all plug into a source of electricity and an electric current runs from your wall socket down the wire and into the appliance. Inside each of the appliances are loops of a special mixture of metals.

The basic idea behind any toaster is simple. A toaster uses infrared radiation to heat a piece of bread. 'Infrared' is a particular kind of light.

The most common way for a toaster to create the infrared radiation is to use 'nichrome', a nickel -based wire wrapped back and forth across a mica sheet.

Electricity cannot pass through this special metal very easily. The metal slows down the electrons and 'holds up' the current flowing through it. This is called the 'resistance' of the metal. Electricity 'flows' or moves through some things better than others do. The measurement of how well something conducts electricity is called its resistance.

Resistance in wire depends on how thick and how long it is and what it is made of.

A piece of metal can be made to act like a heater. When an electrical current occurs, the resistance causes friction and the friction causes heat. The higher the resistance, the hotter it can get. So, a coiled wire that is high in resistance, like the wire in a hair dryer, can be very hot.

When the resistance of a metal is higher, the metal will get hot because of the friction of the electrons in the current of electricity. As the electricity is forced through the wires, the wires begin to heat up and glow very hot. If you look inside your toaster (careful), you'll see those coils or wire glowing orange. It is those coils or loops of wire that cause the bread to go brown, making your toast.

Daily use

A torch, a portable radio, your iPod, mobile phone, television remote control, your wristwatch, all of these run on batteries. Can you imagine your life without these things? Life would certainly be a lot more difficult.

Electricity and Industry

Electricity not only plays a big part in our lives at home, but it is extremely important for all the things that go on in the world around us.

From the huge electric advertising billboards on the side of the road, to the chilled soft drink machine outside the local store, or the factories that produce everything from cars to calculators, every one of these requires electricity to function.

Electricity runs the motors that in turn run most modern machinery. Assembly machines, conveyor belts, baking ovens, copying machines, printers, all these things need electricity in order to run.

Electricity and communication

Radio, television, email, the internet, satellite video link-ups, telephones and faxes all link people in almost every part of the world.

We can dial a friend on our mobile phone, send an email to a relative in another country, turn on the television and watch our favourite show, or go online and find out the latest happenings anywhere on the planet.

And do you know what makes all this possible? Yes, you guessed it, electricity. Modern man has come a long way since the early days of smoke signals, telegraph wires and the snail mail (the old-fashioned way of sending someone a letter).

Electricity and transport

The next time you hop on a train or jump on a bus, or even take a ride in your Dad's car, spare a thought for our good friend electricity. The motor in your car uses spark plugs that create electric sparks to explode the petrol that runs the engine.

Most trains use overhead electric wires to operate, airplanes rely on electronic instruments in order to function, even ocean liners need electricity for their navigation instruments. Eve in deep space, shuttles, satellites and spacecraft depend on electricity in some form or another.

Delivery trucks, toll booths, electronic roadwork signs, airports, train stations, traffic lights and ferries all need electricity in order to operate. Without electricity in our lives we would be doing a lot more walking.

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