Physical Science Unit 8: Lesson 6: Magnetism Lesson 7: Electricity and Magnetism Lesson 8: Lab: Motoring On!

Lesson 6 I can explain a diagram that shows the lines of force in a magnetic field. I can Identify materials that are magnetic. I can compare a magnetic field with an electric field.

Magnetism

Magnets behave in predictable ways. RepulsionAttraction

Bar Magnet Bar magnets are simply pieces of magnetized metal. Click and Drag

What happens when you cut a bar magnet in half? An electrically charged particle can occur with a single positive or negative charge. No matter how you cut a magnet, if it has a south pole, it will have a north pole. Magnetic poles always occur in pairs. Dipolar-An object with two sides that have opposite characteristics.

Opposites Attract If you have 2 bar magnets, the north pole of one will attract the south pole of the other. Unlike poles attract one another.

Likes Repel Like poles repel one another. The north pole of one magnet will repel the north pole of another magnet.

Domains Domain-A tiny region in which adjacent atoms that have magnetic fields line up with their magnetic fields oriented in the same direction.

How are magnets made? Permanent Magnet Bar Magnets Made in a factory All their magnetic material is aligned more in one direction than in others. Overall magnetic force is strong Temporary Magnet Nail Contain magnetic domains Behave like magnets only when in the presence of magnets These items alone do not exert a discernible magnetic force

Magnetic? The refrigerator, alligator paper clip, and nail alone do not exert a discernible magnetic force.

Magnets Exert Force Magnetic Field The space around every magnet where the magnetic force can be felt.

Magnets do not need to touch to exert a force on another object. The magnetic field around a magnet is similar to the electric field around an electric charge. The magnetic field is shown by the iron fillings and the lines.

Earth is a Magnet The Earth behaves like a giant bar magnet. Earth’s geographic north pole is actually close to its magnetic south pole

Lesson 7: I can explain how a magnetic field can be created by an electric current flowing in a wire. I can describe how different variables influence the strength of an electromagnet.

Electricity and Magnetism are Related You can use a changing magnetic field to generate an electric current. You can use moving electric charges to produce a magnetic field in the space around them.

You can use a changing magnetic field to generate an electric current.

Electromagnet A temporary magnet made using electric current, usually running around a metal core.

1.Electricity Source: 2.Metallic Core: 3.Wire:

1. The amount of electric current. 2. The wire Coil

Galvanometers Galvanometer-An instrument used to indicate the presence, direction, or strength of a small electric current. The typical galvanometer is a sensitive laboratory instrument used mainly to detect and compare currents. In the galvanometer, the wire is wound into a coil. When current flows through the coil, one end of the coil becomes a north magnetic pole, the other a south magnetic pole. When a permanent magnet is placed near the coil, the two fields—the one from the coil and the one from the magnet— interact. The like poles will repulse each other and the unlike poles will attract. The amount of attraction and repulsion increases as the strength of the current increases.

A magnetic field can cause an electric charge to move. What happens to the electrons in the wire when we place the battery next to it, but do not move it? What happens when we move the battery?

Lesson 8: Lab: Motoring On! Create an electric motor.