1. Magnetism

2. magnetite (also called lodestone)
Chinese as early as 121 AD knew that an iron rod which had been brought near one of these natural magnets would acquire and retain the magnetic property
magnetite (also called lodestone)

3. WHERE DO YOU FIND OR USE MAGNETS?
Headphones Speakers Phone ringers Seal around refrigerator door Audio tape recording and playback head Video tape recording and playback head Credit card magnetic strip Computer monitor Computer hard drive Power supply transformers Refrigerator magnets Telephone receivers
FANS…bathroom, ceiling
Electric toothbrush
Garage door opener
Cell phone vibrator
Clocks and Watches
High Speed Trains
WHERE DO YOU FIND OR USE MAGNETS?

4. Magnets magnetism – force of attraction or repulsion
not all objects are affected by the force of magnetism
ex. wood, glass, paper, plastic
common metals affected by magnetism are iron, nickel, and cobalt

5. Magnets poles – two ends of a magnet every magnet has two poles
north (N) pole AND south (S) pole
even if you break a magnet in half, each half will have a north pole and a south pole.

6. Properties of Magnets like magnetic poles repel each other
unlike magnetic poles attract each other

7. Magnetic Fields
magnetic field – area around a magnet where magnetic forces can act.

8. Making a Magnet
a material that is easily magnetized tends to lose its magnetism quickly
a magnet made of this kind of material is called a temporary magnet

9. This makes the nail into a temporary magnet.
Making a TEMPORARY Magnet….
An Iron Nail made up of atoms have all electrons spinning in different directions……by rubbing a magnet over the nail in one direction will get the electrons to SPIN all in the SAME direction..
This makes the nail into a temporary magnet.

10. Electromagnets
electromagnet – temporary magnet made by wrapping a current-carrying wire around an iron core
the center of an electromagnet is called the core and is often made of iron.

11. Electromagnets there are two ways to make an electromagnet stronger
increasing the number of coils
increasing the amount of current or voltage

12. Electromagnets
as long as current is flowing, an electromagnet has a magnetic field
electromagnets are useful because they can be turned on and off.
electromagnets have many important uses
ex. radios, telephones, computers

13. The Earth as a Magnet
William Gilbert
a British scientist

14. The Earth as a Magnet
the Earth has a North Magnetic Pole and a South Magnetic Pole

15. The earth is like a giant magnet!
The nickel iron core of the earth gives the earth a magnetic field much like a bar magnet.

16. The Earth as a Magnet
magnetosphere – region of the Earth’s magnetic field

17. The Earth as a Magnet
the magnetosphere traps charged particles from the sun
auroras are also called the northern lights

18. NOW….FUN with Magnets Continue in your notebook my drawing….
How to make a temporary magnet.
How to make an electromagnet.
North/North Poles with iron filings
North/South Poles with iron filing
Lines of force between magnets

19. Magnets and ELECTRICTIY?
Today we look at how magnets are used to create electricity.
In the early 1800s, Michael Faraday discovered “electromagnetic induction” – the scientific way of saying that if he moved a magnet through a loop of wire, the wire would become electrified.

20. a little bit later…….
In 1882, Thomas Edison opened the first full-scale power plant in New York City. Edison’s electric generator was a bigger version of Faraday’s basic experiment – a big magnet rotates around a wire to produce an electric current.
Today’s power plants are bigger and controlled by computers, but the basic process is still the same as it was nearly 120 years ago.

21. Generators
generator – device that changes mechanical energy into electrical energy
a current can be induced in a loop of wire by spinning the loop inside a magnetic field
due to the changing direction of the wire, an alternating current is produced

22. Electricity
A wire passes through a magnetic field will move the electrons in a wire in an alternating motion.

23. Electric Motors
an electric motor is made up of an electromagnet and a permanent magnet

24. Electricity
This is called.. Electromagnetic Induction
Or ELECTRICITY

25. How do you turn a Generator?

26. How do you turn a Turbine?
We convert other forms of energy into Thermal energy (STEAM) to spin the turbine

27. It’s all about the STEAM!

28. A Power Plant….

29. Types of Power Plants COAL Natural Gas Oil Nuclear Hydropower
Wind Power
Solar
Geothermal