In a lab where there wasn’t much action

Two magnets supplied some distraction.

So they matched opposite polesAnd now they’re quite an

attraction.

WHAT IS MAGNETISM AND HOW IS IT LIKE ELECTRICITY?

2000 years agoGreeks found a material that stuck to iron

Found in present day Turkey- that was called Magnesia

They called it MagnetiteWe call it Magnet

1. Have two poles

2. Magnets exert forces

3. Surrounded by magnetic fields.

North and south polesAlways occur in pairs, there will

NEVER be just ONE pole.Magnetic effects are NOT even

through the entire magnet- stronger at the ends- these ends are called POLES

Push or pull exerted by magnetsForce of repulsionForce of attraction

How is this similar to electricity?????

Like poles:Opposite poles:

Area or region around a magnet where magnetic force exists

Unevenly distributed around magnet Strongest at the poles, but exists all

around

Turn to page 185 in the coach, The closer together the lines are, the

stronger the field; the farther apart, the weaker it is.Draw a diagram of magnetic fields into your

notes.

Brain Pop on Magnets:

We’ll also do a magnet lab at some point so you can actually see the

fields.

Ferromagnetism Iron-cobalt-nickel- and alloys

Electromagnetism Made from electricity

_____________Permanent magnets

Always stay magnetizedTemporary magnets

Lose their magnetism

Turn to your neighbor and discuss this question.

After 1 minute, turn to your other neighbor and share what you just

discussed.

Depends on the atomMany electrons are randomly

moving around to and from various atoms.

Sometimes the movement is more arranged.

Moving electrons create magnetic fields that tend to line up alike next to each other. Most fields interfere with or cancel each other out, others do not and…

Some atoms group together and line up more north to south- and have stronger magnetic fields.

Domains are like tons of mini magnets within a large one. They work equally like one large magnet.

Take a look at page 457 (xeroxed packet again)

What are the different kinds of magnets? (we talked about 4 yesterday)

It depends on what atoms the material are made of.

You can also make a magnet from a non-magnetic metal object.

Wipe an iron nail repeatedly the same direction with a bar magnet. This aligns the atoms and domains and creates a stronger magnetic force going in the same direction.

After you magnetize the nail, put it near a paperclip.

What pole is at the point of the nail?

What pole of the paperclip is attracted to the magnetized nail?

How do you know?

How about cutting a magnet in half- won’t that leave only either the north pole or the south pole?

Answer the review questions on page 458 (xeroxed packet)- that is your

ticket out the door.

Can be seen as one giant magnet Acts like there is one huge bar magnet

running through the earth’s core.

Not really-

Earth’s core is too hot for a magnet to be there.

The electrons moving at the core creates magnetic force.

The inner core is solid due to all the pressure, the outer core is liquid.

The liquid outer core flows around as the earth rotates which causes charges to move.

This movement of charges (which charges are moving?- electrons, protons, or neutrons)

Creates a magnetic north and south pole on the earth-on which it rotates.

Magnetic north and south are not exactly geographic N and S, close but not quite.

Generator- uses electromagnets to change KE into electrical E, it generates or makes electricity

Electrical systems in cars- generatorsElectric Motor- changes electrical E to

Kinetic ETransformers- changes the voltage of

the electricity going from the power plant to our houses, changes 3 times, High voltage at the plant, made higher to get it out to

the wires, and then decreased before coming into our homes at 120 volts.

INTERACTION OF MAGNETS AND ELECTRICITY

Hans Oersted- 1800’sFound- pass current in wire, caused magnetic field to form around wire

Current+Wire= magnetic field

- PRODUCTION/interaction OF A MAGNETIC FIELD BY ELECTRICAL CURRENT

The field produced- similar to fields from a bar magnet

SOLENOID: coil of wire w/current- this is an electromagnet

TAKE A LOOK AT PAGE 186 IN THE COACH

1. Place an iron bar inside the coiled wire

2. Coil the wire tighter/increase the number of loops around the iron bar (Strength of the electromagnet increases as the # of coils increases)

3. Increase the current

Scrap metal magnets, high speed trains, doorbells, washers and dryers, ammeters and voltmeters (instruments used by electricians to detect electrical currents)

Anything with a generator has a solenoid.

Anything else????

3- things you learned about electromagnetism

2- applications/examples of electromagnetism

1- draw a diagram in your notes of a basic electromagnet- a solenoid RAISE YOUR HAND WHEN YOU ARE

DONE

If electricity can produce magnetism, can magnets produce electricity?

1831Michael Faraday (GB) & Joseph Henry (US) Independently answered this questionHenry solved first, but Faraday is more

widely recognized for this finding.

Why do you think Faraday (over Henry) is credited with answering this question?

NO CONTACT, ELECTRICITY AND MAGNETISM

Electricity/electric current is ONLY produced when the magnetic fields were CHANGING

Not created with a constant magnetic field or force

Was produced when a magnet moved back and forth within a wire coil.

The faster it moved, the more electricity.

Very importantUsed by power plants to produce

electricity and to get it to our homesWhat resources are used by power

plants to create electricity from electromagnetic induction?

Name the method/device that creates magnetism from electricity.

Name the method and device that makes electricity from magnetism.

Which of the following changes kinetic energy to electrical energy? Electric motor or generator?