1. Magnets and Electromagnets

2. A magnet is any material made of iron or attracted to iron.
What is a magnet?
A magnet is any material made of iron or attracted to iron.

3. Poles of Magnets Magnets have two poles: Opposite poles attract.
North Pole
South Pole
Opposite poles attract.
Same poles repel.

4. Magnetic Fields There are magnetic fields around magnetic poles.
The farther from the pole, the weaker the field.
A stronger magnet has a larger field.

5. What is a domain?
A domain occurs when negatively charged electrons all spin in the same direction and cause magnetism.

6. How to Make a Magnet Rub a conductor against a magnet.
This makes the domains line up.
Now you have a temporary magnet.

7. Magnets can be De-magnetized If:
They are exposed to high temperatures.
They are dropped.
They are placed close to another strong magnetic field.

8. Temporary vs Permanent
Easily magnetized
Loses magnetism easily
Permanent
Difficult to magnetize
Holds magnetism longer

9. Cutting a magnet Each piece will have a north and a south.
Each domain becomes a magnet.

10. The Earth is a Magnet!
There is an imaginary magnet running through the center of the Earth.
The movement of charges on Earth’s surface creates a magnetic field.
Aurora's

11. A compass is a magnet It’s marked “north” end,
points south. (opposites attract)
Geographic
North Pole
South Pole
Magnetic
South Pole
North Pole
Compass N

12. Electromagnet
Solenoid
A temporary magnet made by an electric current producing a magnetic field.
Parts of an electromagnet (see picture)
Wire

13. For an Electromagnet you can:
Turn the magnetic field on and off.
Reverse the direction of the current.
Change the strength by:
Using a larger battery.
Adding more coils to the wire.
Putting the coils closer together.
Changing the core
(bigger or different material)