Notes

1. SPI 0807.12.3 Magnetic Fields Notes Science Learning Intention: Illustrate the field lines and polarity of magnets (Earth, permanent magnets, electromagnets). Purpose: to understand the characteristics of magnetic fields. Success Criteria I will show that I understand this topic by earning a 90 or higher on the quiz. I Can Statement By the end of this unit I will be able to say... ...I can diagram and explain field lines and polarity in magnetic fields.

2. SPI 0807.12.3 Magnetic Fields Notes Science Magnetic Fields • Aninvisible magnetic field exists around all magnets. S N

3. Magnetic Fields • You can see the magnetic field lines by using fine iron filings. Note: field lines are concentrated at the ends (called poles) Note: polarity is the property of having two opposing roles. North Pole South Pole

4. F.Y.I: Why Are Some Substances Magnetic? • All atoms have magnetic fields with north and south poles. • Atoms in objects are found in areas called domains. • If the poles line up facing the same direction, this makes the object magnetic. If they don’t line up, it is not magnetic.

5. Magnetic Poles: North and South • Poles are areas on a magnet that have opposite magnetic qualities (called polarity). • One area is called the north pole. • The opposite area is called the south pole. F.Y.I.- field lines start at the north pole & end at the south pole South Pole North Pole

6. SPI 0807.12.3 Magnetic Fields Notes Science North and South Poles • All magnets have these poles regardless of their shape. • If you cut a magnet in half, each half will still have these two poles (north and south) Donut magnet Horseshoe Magnet Bar magnet

7. SPI 0807.12.3 Magnetic Fields Notes Science Magnetic Forces • magnets exert force on other magnets • “Opposites attract” (North & South pull towards each other) S N N S (North & North or South & South push away) • “Like repels” S N N S

8. Look at the two bar magnets shown below. • Their field lines look as if they are reaching out to each other. • The blue and red ends of these magnets are opposite poles. S N N S Opposites Attract

9. Earth has a powerful magnetic field…the geomagnetic field Earth’s magnetic field is similar to the magnetic field lines of a bar magnet. This magnetic field comes from moving iron particles inside magma deep in the planet’s core

10. SPI 0807.12.3 Magnetic Fields Notes Science Magnetic poles and geographic poles are not the same! Geographic North Earth's north magnetic pole is geographically south (Antarctica) Earth's south magnetic pole is geographically north (Artic) Geographic South Geographic North Magnetic North Magnetic South Geographic South

11. SPI 0807.12.3 Magnetic Fields Notes Science Magnetic South Pole Magnetic North Pole

12. Another name for Earth's magnetic field is the magnetosphere. • The magnetosphere protects us from harmful solar radiation

13. We can see the solar wind hitting Earth's magnetosphere. In the northern hemisphere this is called the Aurora Borealis. In the southern hemisphere this is called the Aurora Australis SPI 0807:12.3 Magnetic Fields Notes Science View this video: Title: "Dance of the Spirits-Northern Lights Link: Northern Ligths Video Clip

14. SPI 0807.12.3 Magnetic Fields Science Questions

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18. SPI 0807:12.3 Magnetic Fields Science Questions