Notes Science

Essential Question(s)What is a magnetic field? What are the similaritiesand differences between the Earth’s magnetic field andthe fields from permanent magnets & electromagnets?

Tennessee SPI Objective:Distinguish among the Earth’s magnetic field and the fields that surround a (permanent) magnet and an electromagnet.

Check for UnderstandingCreate a chart to distinguish among the earth’smagnetic field and the fields that surround a(permanent) magnet and an electromagnet.

SPI 0807:12.3 Magnetic Fields

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Magnetic Fields

Notes SPI 0807:12.3Magnetic 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

Notes SPI 0807:12.3Magnetic Fields Science

You can see the magnetic field lines by using fine iron filings.

Note: - the field lines are concentrated at the ends (called poles)

South Pole

F.Y.I: Why Are Some Substances Magnetic?All atoms have magnetic fields with north and south poles

Notes ScienceSPI 0807:12.2

Electromagnets

If the north and south poles in a domain line up, this makes the object magnetic. If they don’t line up, the object is not magnetic.

Atoms in objects are found in areas called domains.

Magnetic Poles: North and Southareas on a magnet that have opposite magnetic qualities.One area is called the north pole. The opposite area is called the south pole. F.Y.I.-the field lines start at the north pole & end at the south pole

See Holt Online Ch. 16: Sect 1 Visual ConceptTitle: Magnetic Poles

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South Pole

SPI 0807:12.3Magnetic Fields

North and South Poles All magnets have these poles regardless of their shape

Notes ScienceSPI 0807:12.3Magnetic Fields

Horseshoe Magnet

Bar magnet

Donut magnet

Also, 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 ScienceSPI 0807:12.3Magnetic Fields

“Opposites attract”

“Like repels”

(North & South pull towards each other)

(North & North or South & South push away)

See Holt Online: Ch. 16: Sect 1 Visual ConceptTitle: "Earth's Magnetic Field"

Notes SPI 0807:12.3Magnetic Fields Science

Earth is a Giant Magnet Earth has a powerful magnetic field called the geomagnetic field

This magnetic field comes from moving iron particles inside magma deep in the planet’s core

SPI 0807:12.3Magnetic Fields

Geographic North

Geographic South

Now for the confusing part: Earth's north magnetic pole is at the southern end (Antarctica) Earth's south magnetic pole is at the northern end (Arctic Circle)

Magnetic North

Geographic South

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Magnetic SouthGeographic North

Notes SPI 0807:12.3Magnetic Fields Science

Magnetic South Pole

Magnetic North Pole

Notes SPI 0807:12.3Magnetic Fields ScienceAnother name for Earth's magnetic field is the magnetosphere.

The magnetosphere protects us from harmful solar radiation

Notes SPI 0807:12.3Magnetic Fields Science

View this video: Title: "Dance of the Spirits-Northern LightsLink: Northern 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 ScienceSPI 0807:12.3Magnetic Fields

Questions ScienceSPI 0807:12.3Magnetic Fields

Here is an example of a question you might see on a quiz or test.

Questions ScienceSPI 0807:12.3Magnetic Fields

Here is an example of a question you might see on a quiz or test.

Questions ScienceSPI 0807:12.3Magnetic Fields

Here is an example of a question you might see on a quiz or test.

Questions ScienceSPI 0807:12.3Magnetic Fields

Here is an example of a question you might see on a quiz or test.