Presentation on theme: "Electro Magnets What is an electro magnet? How does it work? Where are they used?"— Presentation transcript:
Electro Magnets What is an electro magnet? How does it work? Where are they used?
Electromagnets An electromagnet is simply made of a wire and battery. An electromagnet is produced any time current is flowing through a wire.
Fields Around a Wire The field around a wire is circular and gets weaker as you get further from the wire.
Fields Continued Because the magnetic field around a wire is circular and perpendicular to the wire, an easy way to amplify the wire's magnetic field is to coil the wire, as shown below:
A magnetic nail For example, if you wrap your wire around a nail 10 times, connect the wire to the battery and bring one end of the nail near the compass, you will find that it has a much larger effect on the compass. In fact, the nail behaves just like a bar magnet.
Maglev Trains Maglev is short for magnetic levitation, which means that these trains will float over a guideway using the basic principles of magnets to replace the old steel wheel and track trains. The first maglev train made its debut in Shanghai, China in 2003.
More on Maglev Trains The big difference between a maglev train and a conventional train is that maglev trains do not have an engine -- at least not the kind of engine used to pull typical train cars along steel tracks. The engine for maglev trains is rather inconspicuous. Instead of using fossil fuels, the magnetic field created by the electrified coils in the guideway walls and the track combine to propel the train.conventional trainenginefossil fuels
Maglev Trains The magnetized coil running along the track, called a guideway, repels the large magnets on the train's undercarriage, allowing the train to levitate between 0.39 and 3.93 inches (1 to 10 cm) above the guideway. Once the train is levitated, power is supplied to the coils within the guideway walls to create a unique system of magnetic fields that pull and push the train along the guideway. The electric current supplied to the coils in the guideway walls is constantly alternating to change the polarity of the magnetized coils.
Maglev Trains in the U.S. Plans have been in the works to build a Maglev Train from LA to Pittsburgh, but the cost is very high, so they have not started construction. A prototype train is being built in Georgia by the American Maglev Company.
What else can Electromagnets do? Make a speaker or microphone work. They are used in read/write drives on your computer. Check out the video.video They are used in anything with an electric motor or solenoids. Refrigerators, washer/dryers, vacuum cleaners, electric drills (and other tools), hairdryer, your car (windows, locks, seats), most toys that move, your garage door opener and much more!