1. Notes Science SPI 0807.12.3 Magnetic Fields
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. Notes Science S N SPI 0807.12.3 Magnetic Fields Magnetic Fields
An invisible magnetic field exists around all magnets. N S

3. You can see the magnetic field lines by using fine iron filings.
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. Notes Science SPI 0807.12.3 Magnetic Fields 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)
Bar magnet
Horseshoe Magnet
Donut magnet

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

8. Look at the two bar magnets shown below.
Their field lines look as if they are reaching out to each other. N S
The blue and red ends of these magnets are opposite poles.
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. Magnetic poles and geographic poles are not the same!
SPI
Magnetic Fields
Notes
Science
Magnetic poles and geographic poles are not the same!
Earth's north magnetic pole is geographically south (Antarctica)
Earth's south magnetic pole is geographically north (Artic)
Geographic North
Geographic South
Geographic North
Magnetic North
Magnetic South
Geographic South

11. Notes Science SPI 0807.12.3 Magnetic Fields 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. Notes Science SPI 0807:12.3 Magnetic Fields
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
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Science
View this video: Title: "Dance of the Spirits-Northern Lights
Link: Northern Ligths Video Clip

14. SPI
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