TYPES OF MAGNETS• Permanent• Temporary• Electromagnets

MAGNETAn object that attracts certain materialsIron and steel

MAGNETSMagnetism: force exerted by a magnet

Magnetic Poles: part of magnet where force is strongestEvery magnet has 2 poles (North & South)

Opposites attractLike repelBreak a magnet = 2 new magnets

MAGNETSMagnetic field: region around magnet in which magnet exerts forceMagnetic field lines

MAGNETSMagnetic domain: group of atoms whose magnetic fields are aligned

MAGNETSPermanent and temporary magnetsDropExpose to high temperatures

Earth: magnetic field

ELECTROMAGNETISMMagnetism that results from an electric currentCharge particle---electron---moves and creates a magnetic field

List 3 ways that the strength of an electromagnet can be controlled.

What are the 2 benefits of an electromagnet?

ELECTROMAGNETMagnet made by placing a piece of iron or steel (ferromagnetic core) inside a coil of wire

ELECTROMAGNET

ELECTROMAGNETCan be turned off and onCan control the strength of the magnet

Voltage source (increase = increase strength)

# times coil is wrapped around the core (increase # = increase strength)

How close together the coils are (closer = increase strength)

Size of ferromagnetic core (increase size = increase strength)

MAGNETS--CURRENT Magnets can be used to generate

electric current.Generator: a device that converts

the energy of motion (kinetic energy) into electrical energy

Shaft of generator turnsRotation of shaft causes coils of wire

to spin---creates a magnetic fieldCoils cross magnetic field line-----

electric current created

MAGNETS--CURRENTDirect current

Electric charge flows in ONE direction

Produced by batteriesAlternating current

Flow of electric charge that reverses direction at regular intervals

Home and school

MAGNETS--CURRENTTransformer

A device that increase or decreases voltage

Use magnetism to control the amount of voltage

Consists of 2 coils of wire wrapped around an iron ring

MAGNETS--CURRENT

WattUnit of measurement for power