ElectroMagnetism

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Electro-Magnetism
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What is an electromagnet?

• The basic idea behind an electromagnet is
  extremely simple By running electric current
  through a wire, you can create a magnetic field.
• By using this simple principle, you can create
  all sorts of things, including motors, solenoids,
  read/write heads for hard disks and tape drives,
  and speakers.

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Something to think about..

• What is the difference between a permanent magnet
  and an electromagnet?
• Permanent magnets come from nature and are
  attracted to any metal which contains iron.
• Electromagnets are temporary, their magnetism is
  only present when electricity is applied to them.
• This makes electromagnets very useful for
  different applications.

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Anatomy of an Electromagnet

• An electromagnet starts with a battery (or some
  other source of power) and a wire. What a battery
  produces is electrons.
• Electrons collect at the negative end of the
  battery, and, if you let them, they will gladly
  flow to the positive end. Electrons will flow
  from the negative side of the battery to the
  positive side as fast as they can.
• A small magnetic field is generated in the wire.
  It is this small magnetic field that is the basis
  of an electromagnet.

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Types of Electromagnets
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The Magnetic Coil

• The next picture shows the shape of the magnetic
  field around the wire. In this figure, imagine
  that you have cut the wire and are looking at it
  end-on.

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So what is a solenoid?

• A solenoid is another form of electromagnet.
• It is an electromagnetic tube generally used to
  move a piece of metal linearly.
• If your car has power locks, they may operate
  using a solenoid.

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A quick review...

• Permanent magnets never loose their magnetism
  unless destroyed.
• Electromagnetism is created when electrons flow
  within an electrical circuit.
• Electromagnets can be used for a number of
  different applications.
• Solenoids use electromagnetism to create linear
  motion.

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Lets try an experiment, find a partner and meet
me by the round tables! )