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Magnetic Fields
• A magnetic field consists of imaginary lines of flux moving
around a magnet where the magnetic force is exerted
• Magnetic field lines always form loops.
The lines represent the
invisible magnetic field
surrounding a magnet
The Earth itself is a magnet, with a magnetic north
pole and south pole.
S
N
The origin of the Earth’s magnetic field is
said to be a result of the electric currents
produced by the rotation of the ironnickel core.
The Earth’s magnetic field
continually traps moving
charged particles coming from
the sun, called solar wind.
What is a Magnet?
• A magnet is anything that attracts materials that has a
magnetic field and will attract materials like iron, nickel and
cobalt.
• A material that has strong magnetic properties is called
ferromagnetic (ferrum is a latin word for iron.)
Uses for Magnets
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•
•
•
•
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Holding things on your refrigerator!
Credit cards
Computers
Electronics
Compasses
And many more!
Properties of Magnets
• Magnets attract when the OPPOSITE POLES of
two magnetic objects are close to each other.
• Magnets also strongly attract ferromagnetic
materials such as iron, nickel and cobalt.
• Magnets Repel when LIKE POLES are facing each
other, the magnetic force pushes them apart
• Part of a free swinging magnet always points in the
direction of north (like in a compass!)
Magnetic Poles
• We call the ends of magnets “poles”
• ALL magnets have a north (N) pole
and a south (S) pole.
• Like poles repel
• Opposite poles attract
Magnetic Poles
How it looks throughout the object
Electrons
• Electrons are tiny negative particles
that surround an atom and are
what give magnets their magnetic
properties
• Spinning electrons produce a
magnetic field
• When many electrons are spinning
in the same directions those
individual magnetic fields combine
to form a stronger magnet