MagnetismMagnetism

Magnetism – the attraction or repulsion of magnetic materials

History of MagnetismHistory of Magnetism

Magnetism was discovered in Magnesia Magnetism was discovered in Magnesia Greece (which is now Turkey)Greece (which is now Turkey)

A mineral in rocks that is magnetic was A mineral in rocks that is magnetic was discovered. This mineral was called discovered. This mineral was called magnetite. The name of these rocks are magnetite. The name of these rocks are called lodestones.called lodestones.

Magnetism was discovered in Magnesia Magnetism was discovered in Magnesia Greece (which is now Turkey)Greece (which is now Turkey)

A mineral in rocks that is magnetic was A mineral in rocks that is magnetic was discovered. This mineral was called discovered. This mineral was called magnetite. The name of these rocks are magnetite. The name of these rocks are called lodestones.called lodestones.

Three Properties of MagnetsThree Properties of Magnets

Allowed to swing freely, one part of a Allowed to swing freely, one part of a magnet will always point North.magnet will always point North.

Magnets contain iron and are attracted Magnets contain iron and are attracted to materials that are made of iron.to materials that are made of iron.

Magnets attract and repel other Magnets attract and repel other magnets.magnets.

Allowed to swing freely, one part of a Allowed to swing freely, one part of a magnet will always point North.magnet will always point North.

Magnets contain iron and are attracted Magnets contain iron and are attracted to materials that are made of iron.to materials that are made of iron.

Magnets attract and repel other Magnets attract and repel other magnets.magnets.

Magnetic PolesMagnetic Poles

All magnets have a North and South All magnets have a North and South Pole. At the poles is where a magnet is Pole. At the poles is where a magnet is the strongest.the strongest.

Like poles repel each other.Like poles repel each other.Opposite poles attract each other.Opposite poles attract each other.

All magnets have a North and South All magnets have a North and South Pole. At the poles is where a magnet is Pole. At the poles is where a magnet is the strongest.the strongest.

Like poles repel each other.Like poles repel each other.Opposite poles attract each other.Opposite poles attract each other.

Magnetic FieldsMagnetic Fields

The region around a magnet in which magnetic forces act.

Magnetic EarthEarth is compared to a bar magnet because it has

a magnetic field, poles, and its core consists of iron and nickel.

Magnetic EarthEarth is compared to a bar magnet because it has

a magnetic field, poles, and its core consists of iron and nickel.

Structure of the AtomStructure of the Atom

Spinning electronsproduce a magneticfield. This makes theelectrons behave like tiny magnets.

Magnetic DomainsMagnetic Domains

Magnetic domains are groups of atoms Magnetic domains are groups of atoms that have their magnetic fields aligned.that have their magnetic fields aligned.

Magnetized materials have their Magnetized materials have their domains arranged in the same direction.domains arranged in the same direction.

Magnetic domains are groups of atoms Magnetic domains are groups of atoms that have their magnetic fields aligned.that have their magnetic fields aligned.

Magnetized materials have their Magnetized materials have their domains arranged in the same direction.domains arranged in the same direction.

Ferromagnetic MaterialsFerromagnetic Materials

Ferro comes from ferrum which means Ferro comes from ferrum which means iron in Latin.iron in Latin.

Ferromagnetic materials are materials Ferromagnetic materials are materials that show strong magnetic properties.that show strong magnetic properties.

Examples: iron, nickel, cobalt, Examples: iron, nickel, cobalt, gadolinium, samarium, neodymiumgadolinium, samarium, neodymium

Ferro comes from ferrum which means Ferro comes from ferrum which means iron in Latin.iron in Latin.

Ferromagnetic materials are materials Ferromagnetic materials are materials that show strong magnetic properties.that show strong magnetic properties.

Examples: iron, nickel, cobalt, Examples: iron, nickel, cobalt, gadolinium, samarium, neodymiumgadolinium, samarium, neodymium

Making, Changing, and Destroying Magnets

Making, Changing, and Destroying Magnets

Permanent magnets are made from Permanent magnets are made from materials that keep their magnetism.materials that keep their magnetism.

Temporary magnets are made from Temporary magnets are made from materials the easily lose their materials the easily lose their magnetism.magnetism.

Heating a magnet, stroking a magnet Heating a magnet, stroking a magnet back and forth with another magnet, back and forth with another magnet, and striking/dropping a magnet can and striking/dropping a magnet can destroy its magnetism.destroy its magnetism.

Permanent magnets are made from Permanent magnets are made from materials that keep their magnetism.materials that keep their magnetism.

Temporary magnets are made from Temporary magnets are made from materials the easily lose their materials the easily lose their magnetism.magnetism.

Heating a magnet, stroking a magnet Heating a magnet, stroking a magnet back and forth with another magnet, back and forth with another magnet, and striking/dropping a magnet can and striking/dropping a magnet can destroy its magnetism.destroy its magnetism.

Breaking MagnetsBreaking Magnets

If a magnet is broken in two, you end up If a magnet is broken in two, you end up with two magnets each with a North and with two magnets each with a North and South pole.South pole.

If a magnet is broken in two, you end up If a magnet is broken in two, you end up with two magnets each with a North and with two magnets each with a North and South pole.South pole.

ElectromagnetismElectromagnetism

Electric Current and MagnetismElectric Current and Magnetism

An electric current produces a magnetic An electric current produces a magnetic field.field.

The relationship between electricity and The relationship between electricity and magnetism is called magnetism is called electromagnetismelectromagnetism..

An electric current produces a magnetic An electric current produces a magnetic field.field.

The relationship between electricity and The relationship between electricity and magnetism is called magnetism is called electromagnetismelectromagnetism..

SolenoidsSolenoids

A A solenoidsolenoid is a coil of wire with a is a coil of wire with a current.current.

The more coils a solenoid has the The more coils a solenoid has the stronger the magnetic field. stronger the magnetic field.

A A solenoidsolenoid is a coil of wire with a is a coil of wire with a current.current.

The more coils a solenoid has the The more coils a solenoid has the stronger the magnetic field. stronger the magnetic field.

ElectromagnetsElectromagnets

An An electromagnetelectromagnet is a solenoid with a is a solenoid with a ferromagnetic core.ferromagnetic core.

This type of magnet can be turned on This type of magnet can be turned on and off.and off.

An An electromagnetelectromagnet is a solenoid with a is a solenoid with a ferromagnetic core.ferromagnetic core.

This type of magnet can be turned on This type of magnet can be turned on and off.and off.

Increasing the Strength of an Electromagnet

Increasing the Strength of an Electromagnet

Use a stronger ferromagnetic coreUse a stronger ferromagnetic coreAdd more coils to the solenoidAdd more coils to the solenoidWind the coils of the solenoid closer Wind the coils of the solenoid closer

togethertogether Increase the electrical current by adding Increase the electrical current by adding

more voltage.more voltage.

Use a stronger ferromagnetic coreUse a stronger ferromagnetic coreAdd more coils to the solenoidAdd more coils to the solenoidWind the coils of the solenoid closer Wind the coils of the solenoid closer

togethertogether Increase the electrical current by adding Increase the electrical current by adding

more voltage.more voltage.

Uses of ElectromagnetsUses of Electromagnets

Junkyard Cranes, Circuit Breakers, andJunkyard Cranes, Circuit Breakers, and MRI’s just to name a few.MRI’s just to name a few.

Junkyard Cranes, Circuit Breakers, andJunkyard Cranes, Circuit Breakers, and MRI’s just to name a few.MRI’s just to name a few.