Magnetism

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Slide 45

The solar wind is constantly bombarding the Earth’s magnetic field. Sometimes these charged particles penetrate that field. These particles are found in two large regions known as the Van Allen Belts.

Slide 46

The Earth’s magnetic field extends far into space. It is called the “magnetosphere.” When the magnetic particles from the sun, called “solar wind”, strike this magnetosphere, we see a phenomenon called…

Slide 47

The Aurora Borealis in the Northern Hemisphere

And the Aurora Australis in the Southern Hemisphere

Slide 48

Slide 49

Electricity and Magnetism

Electric forces hold atoms and molecules together.

Electricity controls our thinking, feeling, muscles and metabolic processes.

Electricity and magnetism underpin much of our current technology (e.g. computers).

Electricity and magnetism are linked on a fundamental level.

Slide 50

Electric Motor

An electric motor, is a machine which converts electrical energy into mechanical (rotational or kinetic) energy.

A current is passed through a loop which is immersed in a magnetic field. A force exists on the top leg of the loop which pulls the loop out of the paper, while a force on the bottom leg of the loop pushes the loop into the paper.

The net effect of these forces is to rotate the loop.

Slide 51

Electromagnet (Magnetism from Electricity)

An electromagnet is simply a coil of wires which, when a current is passed through, generate a magnetic field, as below.

Slide 52

Magnetic Properties of Matter

In other words….materials which produce magnetic fields with no apparent circulation of charge.

All substances - solid, gas, and liquid - react to the presence of a magnetic field on some level. Remember why?

How much they react causes them to be put into several material “types”.

Slide 53

Top Ten List

1. There are North Poles and South Poles.

2. Like poles repel, unlike poles attract.

3. Magnetic forces attract only magnetic materials.

4. Magnetic forces act at a distance.

5. While magnetized, temporary magnets act like permanent magnets.

What We Will Learn About Magnetism