1. Warm-Up What equation do we get from Ohm’s Law?
What is the equation for electrical power?

2. Worksheet Ohm’s Law & Power Practice Problems
You will have 40 minutes to work on these problems.
If you do not finish, it will be hw.

3. What is a magnet?
Describe in your own words what a magnet is.

4. What is Magnetism?
Force of attraction or repulsion due to electron arrangement
Magnetic forces are the strongest at the poles
Magnets have two poles: North and South

5. Magnetic Poles and Fields
Magnets always have two poles
If a magnet is cut it will still have two poles
Why do you think this is?
Like magnetic poles repel
Unlike magnetic poles attract
A magnetic field is the area in which magnetic forces act

6. Earth’s Magnetic Properties
Gilbert was a scientist that showed that the Earth behaves as a magnet
The Earth’s magnetic field is strongest at the poles
Earth’s magnetic field is called the magnetosphere

7. Compasses Compasses are used to determine direction
How do compasses help us determine direction?
Compass needles are magnetized and respond to the magnetic field of the Earth
Compasses point to the
MAGNETIC POLES OF THE EARTH

8. Electromagnetism Discovered by Oersted (scientist)
Relationship between electricity and magnetism

9. What is an Electromagnet?
Electromagnet – a magnet made from a current bearing coil of wire wrapped around an iron or steel core.

10. Increasing the Strength of Electromagnets
Increase the voltage or current
Increase the number of loops of wire

11. What is a Generator?
Generator – a machine that changes mechanical energy to electrical energy
It moves a magnet near a wire to create a steady flow of electrons.
This creates currents in coils of wire.
 The action that forces this movement varies greatly, ranging from hand cranks and steam engines to nuclear fission, but the principle remains the same.

12. Recall the bike…
Explain how peddling the bike produced the current to light the light bulbs?

13. What is a Motor?
Motor – a device that changes electrical energy to mechanical energy that can do work.
Why would this be useful?

14. Electric Motors vs. Generators
Electric motors convert electricity to mechanical energy in order to do work
Generators convert mechanical energy to electrical energy

15. That’s All Folks !!!! Begin working on your FINAL EXAM REVIEW.
REMEMBER: All missing work and corrections are due Friday, May 16th