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Study guide
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Facts About Magnets and Magnetism
A magnet is a rock or metal that has the power to attract certain other metals
like iron and steel: A typical magnet has two poles, or ends, called the north and
south poles. Two like poles always repel, or push away, from each other. Two
unlike, or opposite, poles always attract. The magnetic field is the area around
the magnet affected by the magnet's force.
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Kinds of Magnets
Permanent magnets keep their magnetism. Temporary magnets are
objects that can be magnetized by a magnetic source, but lose their power after
the source is removed. Electromagnets are made by sending electricity
through a wire coil wrapped around an iron rod.
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' "^ Uses of Magnets
Bar magnets are used as compass needles and door latches. A horseshoe
magnet is a bent bar magnet used itfsome small motors like those in slot cars.
Circular magnets do not have poles, instead, the magnetism runs in a circle..
They are used in large computers. Disk magnets have one pole around the
edge and the other in the center. They are used in speakers. Cylindrical
magnets are used in electric meters and to hold objects in place on machines.
Electromagnets are used in telephones and doorbells and to lift heavy iron
and steel.
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History of Magnetism
Long ago magnetism was discovered in lodestone, a natural rock that
attracts iron. The earliest compasses used lodestone.
The Earth's Magnetic Field
The earth itself has a magnetic field and acts like a giant bar magnet. The
magnetic poles are located near the earth's North and South Poles.
a Frank Schaffer Publications. Inc.
FS-2418 Magnets at Work
Magnets and Their Uses
Ask your students to name different kinds of magnets and to list ways magnets are used. On chart paper,
create a concept web to organize your students' responses.
Kinds of Magnets
Uses of Magnets
horseshoe magnets
bar magnets
rod magnets
U-shaped magnets
round magnets
square magnets
doughnut-shaped magnets
electromagnets
natural magnets (lodestone
made of magnetite and
the planet earth)
refrigerator door
cabinets
electric can opener
magnetic screwdriver
cranes in junkyards
compass needle
telephone
door bell
television
computers and computer disks
electric motors in washing
machines and vacuums
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Magnets and Their Uses
Ask your students to name drtferent kinds of magnets and to list ways magnets are used. On chart paper,
create a concept web to organize your students' responses.
Kinds of Magnets
Uses of Magnets
horseshoe magnets
bar magnets
rod magnets
U-shaped magnets
round magnets
square magnets
doughnut-shaped magnets
electromagnets
natural magnets (lodestone
made of magnetite and
the planet earth)
refrigerator door
cabinets
electric can opener
magnetic screwdriver
cranes in junkyards
compass needle
telephone
door bell
television
computers and computer disks
electric motors in washing
machines and vacuums