1. Welcome Back Minions!!! 2 days to go...

2. Whatayathink… What is electromagnetism? What are the 3 characteristics found in a magnetic field produced by a current? What is an electromagnet?

3. Discovery! 1820 Hans Christian Ørsted – Danish Physicist & Chemist Experiment – Current through a wire Brought a compass near – The needle moved!

4. He did what?

5. What is this? Electric current produces a magnetic field. Electromagnetism – Relationship between electricity and magnetism.

6. Three Characteristics… Magnetic field produced by a current has 3 characteristics… – 1) Field can be turned on or off. – 2) Field can have its direction reversed. – 3) Field can have its strength changed.

7. Turn it On/Off… Example of this is an electromagnet at a scrap yard. – Turn current on. Magnet picks up metal. – Turn current off. Magnet drops metal.

8. Reversed! What do you notice about the current? What do you notice about the field? What happens when you switch the current?

9. Stronger! When a wire is looped it bunches up the magnetic field, increasing its strength. The more loops, the greater the strength! Solenoid – A coil of wire with a current

10. Stronger! 4 Ways… – Increase the current! – Add more loops of wire! – Wind the coils closer together! – Stronger ferromagnetic material for the core!

11. Make your own magnet! Battery Wire Metal rod or nail

12. Look familiar?

13. Electromagnet What is it? – Solenoid with a ferromagnetic core. Produced by the current and the core! Overall magnetic field is hundreds or thousands of times stronger than the field produced by a current alone! It can be turned on and off!

14. Electromagnet Remember the crane with the electromagnet?

15. Review… 1)Discovered the electromagnet. 2)Discovered magnets had an electrical field. 3)Discovered currents had a magnetic field. 4)Discovered compasses are not affected by currents.

16. Review… Electromagnetism is… 1) Sticky for metals. 2) Relationship between electricity and magnetism. 3) Useless in space. 4) Relationship between magnets and wire coils.

17. Review… What are the 3 characteristics found in a magnetic field produced by a current? 1) Turned on/off, repels plastic, strength changed. 2) Turned on/off, direction reversed, series circuit. 3) Fireproof, direction reversed, strength changed. 4) Turned on/off, direction reversed, strength changed.

18. Review… What is an electromagnet? 1) Solenoid with a ferromagnetic core. 2) Series circuit with an iron core. 3) Parallel circuit with a reversed current. 4) Comic book villain.