1. ELECTROMAGNETS

2. REVIEW All matter has protons & electrons Electric current is the flow of charge through a material Amount of charge that passes through wire in a unit of time is rate of current flow

3. RELATING ELECTRICITY TO MAGNETS Electric current creates magnetic field Any electrical charge in motion creates magnetic field Direction of current determines direction of magnetic field Reverse current, magnetic field reverses Can control a magnetic field by using an electric current

4. SOLENOIDS Current carrying coil of wire with many loops Creates magnetic field that can be turned on & off by switching the current on & off

5. USES OF ELECTROMAGNETS Lifting heavy pieces of scrap metal Recording information on audiotapes, videotapes, computer disks, or credit cards Talk into a microphone, the vibrations of your voice are change into an electric current Current is used in an electromagnet in the recoding head of the tape recorder to produce magnetic field

6. WAYS TO INCREASE STRENGTH OF ELECTROMAGNET Increase current in the solenoid Add more loops of the wire Wind the coils closer together Using stronger ferromagnetic material as core

7. https://www.youtube.com/watch?v=emlzh9XXWgQ

8. HOW TO GET ELECTRICITY TO YOUR HOUSE http://www.childrensuniversity.manchester.ac.uk/interactives/science/energ y/electricity/ http://www.childrensuniversity.manchester.ac.uk/interactives/science/energ y/electricity/

9. ASSESSMENT! The region in which magnetic forces act is called a Line of force Pole Magnetic field Field of attraction

10. An example of a ferromagnetic material is Plastic Wood Copper iron

11. The person who first suggested that Earth behaves as a magnet was Ampere Oersted Gilbert Columbus

12. The region in which Earth’s magnetic field is found is called the Atmosphere Stratosphere Aurora magnetosphere

13. A coil of current-carrying wire with an iron core is called Ferromagnet Electromagnet Compass Maglev

14. TRUE OR FALSE If false, replace the underlined word to make it true Like poles of magnets repel each other The type of magnetic mineral found in nature is called platinum A compass needle points in the direction of Earth’s geographic north pole You can increase the strength of an electromagnet by adding more turns of a wire to it

15. Explain why you are not left with one north pole and one south pole if you break a magnet in half.

16. How does a material become magnetic?

17. How does Earth act like a magnet?

18. What is an aurora? How is it produced?

19. Why does a compass needle change direction when it is placed near a current-carrying wire? The created magnetic field interferes with Earth’s magnetic field