Electromagnets

EQ: What is an electromagnet? SPI 0807.12.2

What’s an Electromagnet?

• Electromagnet: the interaction between electricity and magnetism.

• Electromagnets are devices that create a magnetic field through the application of electricity.

• Common electromagnets: Doorbells and motors

Electromagnets are made out of a length of conductive wire, usually copper, wrapped around a piece of metal.

How do electromagnets work?

1. An electric current is introduced, either from a battery or another source of electricity, and flows through the wire.

2. This creates a magnetic field around the coiled wire, turning the metal into a magnet.

** Electromagnets are useful because you can turn the magnet on and off.

Wrecking yards employ extremely powerful electromagnets to move heavy pieces of scrap metal or even entire cars from one place to another.

How to build an electromagnet

The MORE loops, the GREATER the magnetic field.

EQ: Can electricity be produced using a magnet and a wire coil?

SPI 0807.12.1

Electricity from a Magnet

Electricity from Magnetism

• Electromagnetic induction- the process of creating an electric current in a circuit by changing a magnetic field.

Electromagnetic Induction

• Electromagnetic Induction was discovered by Michael Faraday.

• He discovered that moving a magnet near a wire will cause an electric current to flow through the wire.

Air Force Video

Every magnet is surrounded by a _______________.MAGNETIC FIELD

• When a magnet is moved near a wire, the magnetic field of the magnet reacts with the electrons in the wire and causes them to move in a certain direction.

If there is no magnet near, there can be no electrical current.

When the magnet is placed

inside, an electric current

is produced.

Electricity from Magnetism

You can change the magnetic field by doing any of the following…

1.

Move

a

magnet through

a coil

of

wire.

2. Moving a wire between the poles of a magnet.

3. Turning a loop of wire between the poles of a magnet.

Examples of electromagnetic induction:

Electric generators

Transformers

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