Transcript Electromagnets

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.
The MORE loops, the GREATER the
magnetic field.
How to build an electromagnet
Electricity from a Magnet
EQ: Can electricity be produced using a
magnet and a wire coil?
SPI 0807.12.1
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…
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
Brainpop