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Magnetism Notes #2

Magnetism Notes #2. Mr. Magnetism? What if the magnet broke? What happens? *Although magnets ___________…

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What if the magnet broke? What happens? *Although magnets ___________ and ___________ each other, the DO NOT have __________ poles! You get more magnets! (each piece now has a north and south pole) attractrepel + or -

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Page 1: Magnetism Notes #2. Mr. Magnetism? What if the magnet broke? What happens? *Although magnets ___________…

MagnetismNotes #2

Page 2: Magnetism Notes #2. Mr. Magnetism? What if the magnet broke? What happens? *Although magnets ___________…

Mr. Magnetism?

Page 3: Magnetism Notes #2. Mr. Magnetism? What if the magnet broke? What happens? *Although magnets ___________…

What if the magnet broke?

What happens?

*Although magnets ___________ and ___________ each other, the DO NOT have __________ poles!

You get more magnets!(each piece now has a north and south pole)

attract repel+ or -

Page 4: Magnetism Notes #2. Mr. Magnetism? What if the magnet broke? What happens? *Although magnets ___________…

Creating a Magnet How to magnetize an object:To make a strong magnet:

To make a weak magnet:

How do you make a compass?

Heat up the ferrous object and let it cool in the presence of a magnetic field. When completely cooled, it will be magnetized. (For example: ancient clay pots & lava)

Let a ferrous object sit in the presence of a B-field

Balance a bar magnet on a point so that it can spin freely

Page 5: Magnetism Notes #2. Mr. Magnetism? What if the magnet broke? What happens? *Although magnets ___________…

Ancient Clay Pots

What do we use ancient clay pots for?

We collect data from these pots in order to chart the decline of the Earth’s magnetic field.

Page 6: Magnetism Notes #2. Mr. Magnetism? What if the magnet broke? What happens? *Although magnets ___________…

Magnetic Field Reversals

End of the world???

•Using data from cooled volcanic lava, we know that it reverses about every 200,000 years.

•The last reversal was 780,000 years ago!

Page 7: Magnetism Notes #2. Mr. Magnetism? What if the magnet broke? What happens? *Although magnets ___________…

Destroying a Magnet

What does it mean to demagnetize something?

How do you do it?

To make the e- spins of all the domains random

1.) Influence it by an outside magnet2.) Hit it with an object or drop it3.) Heat it up

Page 8: Magnetism Notes #2. Mr. Magnetism? What if the magnet broke? What happens? *Although magnets ___________…

Electric Current

How does electric current relate to magnetism?

So what would happen to a compass that is placed on a wire with current flowing through it?

Electric current flowing through a wire generates a looping magnetic field around the wire.

It would be influenced by the magnetic field and no longer point towards north

Page 9: Magnetism Notes #2. Mr. Magnetism? What if the magnet broke? What happens? *Although magnets ___________…

Car Example Solenoid:What is it?

How does it work?

Why is it bad if your car battery dies?

In a car or truck, the starter solenoid is part of the starter system. The starter solenoid receives a large electric current from the car battery and a small electric current from the ignition switch.

When the ignition switch is turned on , the small electric current forces the starter solenoid to relay a large electric current from the battery to the starter motor.