Notes Science Essential Question(s) 1) What is a magnetic field? 2) Compare and contrast Earth’s magnetic field and the fields from permanent magnets and/or electromagnets. Tennessee SPI Objective: Distinguish among the Earth’s magnetic field and the fields that surround a (permanent) magnet and an electromagnet. Check for Understanding Create a chart to distinguish among the earth’s magnetic field and the fields from permanent magnets and electromagnets. SPI 0807:12.3 Magnetic Fields Instructions for Students 1) Make sure you view this presentation in slideshow mode. 2) You can find instructions about how to do this by doing a Google search or by searching YouTube. 3) After you have it in slideshow mode, press the right-arrow keyboard button to advance through the presentation. 4) If you need help, please communicate with your teacher.

Magnetic Fields Notes SPI 0807:12.3 Magnetic Fields Science  An invisible magnetic field exists around all magnets. See Holt Online: Ch. 16: Sect 1 Visual Concept Title: Magnetic Fields N S

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

F.Y.I: Why Are Some Substances Magnetic?  All atoms have magnetic fields with north and south poles. Notes Science SPI 0807:12.2 Electromagnets  If the poles line up facing the same direction, this makes the object magnetic. If they don’t line up, it is not magnetic.  Atoms in objects are found in areas called domains.

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 See Holt Online Ch. 16: Sect 1 Visual Concept Title: Magnetic Poles South Pole North Pole

North and South Poles  All magnets have these poles regardless of their shape Notes Science SPI 0807:12.3 Magnetic Fields Horseshoe Magnet Bar magnet Donut magnet  If you cut a magnet in half, each half will still have these two poles (north and south)

Magnetic Forces  magnets exert force on other magnets Notes Science SPI 0807:12.3 Magnetic Fields  “Opposites attract”  “Like repels” (North & South pull towards each other) (North & North or South & South push away) NNS S N NS S

Earth has a powerful magnetic field…the geomagnetic field This magnetic field comes from moving iron particles inside magma deep in the planet’s core See Holt Online: Ch. 16: Sect 1 Visual Concept Title: "Earth's Magnetic Field"

SPI 0807:12.3 Magnetic Fields Geographic North Geographic South Earth's north magnetic pole is geographically south (Antarctica) Magnetic North Geographic South Notes Science Magnetic South Geographic North Magnetic poles and geographic poles are not the same! Earth's south magnetic pole is geographically north (Artic)

Notes SPI 0807:12.3 Magnetic Fields Science Magnetic South Pole Magnetic North Pole

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

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

Here is an example of a question you might see on a quiz or test. Questions Science SPI 0807:12.3 Magnetic Fields

Questions Science SPI 0807:12.3 Magnetic Fields Here is an example of a question you might see on a quiz or test.

Questions Science SPI 0807:12.3 Magnetic Fields Here is an example of a question you might see on a quiz or test.

Questions Science SPI 0807:12.3 Magnetic Fields Here is an example of a question you might see on a quiz or test.

Questions Science SPI 0807:12.3 Magnetic Fields Here is an example of a question you might see on a quiz or test.