1. Earth’s Magnetic Field
Chapter 14
Lesson 3

2. A magnet is any material that attracts iron and materials that contain iron.
What is a Magnet?

3. Magnetic Poles Any magnet has two ends, a north and a south pole.
Magnetic poles that are alike repel each other.
Magnetic poles that are unalike attract each other.
Remember: “Opposites Attract!”
Where is the magnetic force is the strongest?
At the poles
Magnetic Poles

4. The area of magnetic force around the magnet is known as its magnetic field.
The field lines form loops from pole to pole, and never cross.
Magnetic Field

5. Use the provided magnets and ziplock bag of iron filings to view the magnetic field.
Where are most of the iron filings at?
What does this tell you about the strength of the magnet?
Test the theory of attraction and repulsion of the North and South poles.
Magnetic Activity

6. Earth’s Magnetic Field
Just like a bar magnet, Earth has a magnetic field around it and two magnetic poles.
Compasses are devices that have a magnetic needle that spins freely.
Earth’s Magnetic Field

7. Earth’s Magnetic Field
Earth has a magnetic field because of the outer core (liquid iron) and inner core (solid iron) moving at different speeds.
Earth’s Magnetic Field

8. Earth’s Magnetic Field
The magnetic poles are not in the same place as the geographic poles. The difference (angle) between the geographic north pole and the magnetic pole is known as magnetic declination.
Earth’s Magnetic Field

9. Earth’s Protection

10. Earth’s Magnetic Field

11. Electricity and Magnetism