The Electricity and Magnetism Connection

Chapter 5 Activity 3

What happens when you put the magnet near the compass? How does this happen? The compass points to the magnet. If the magnet is next to the compass the

needle goes crazy. The needle is a magnetized metal so it is

attracted to the magnet itself

Warm-Up Read “What Do You

Think” on page 264. Record you ideas

about this question in your comp book

Now discuss your answers with the person sitting next to you

Activity Read and Answer the “For You To Do” on

pages265-267 Make sure to record you answer in you comp

book

For You To Do

Review – Electricity and Magnetism ConnectionWhat does it mean?We can make magnet using electricity and we can use electricity to make a magnet. This is what is meant by the electricity and magnetism connection.

How do we know?We put the wire with the battery and the wire became magnetic. Because when you run a electricity through a wire it makes a magnetic field.

Why do we believe?Metal detectors use electricity to power magnets that can detect metals. If the find a strong metal the metal detector goes off letting us know that someone has a lot of metal.

Why should I care?

Why do we believe?

Magnetic Fields An Electric current has a

magnetic field. For a long, straight wire, the magnetic field makes concentric circles around the wire.

As distance from the wire increases, the field becomes weaker. To make a stronger field, bend the wire into a loop.

Magnetic Fields continued A changing magnetic field

through a loop of wire induces a current in the wire.

Moving the loop near a magnet produces such a changing field (because the magnetic field is not uniform).

Through this process, which is called current induction, generators in power plants produce electricity. Current induction depends only on relative motion

Magnetism continued In Step 12, you will

connect several batteries in series to increase the current through the electromagnet.

Increasing the current will increase the strength of the electromagnet, But there is a limit to this increase, because once all the domains are lined up, no further magnetism can be obtained from the nail. This effect is called saturation.