Unit 1

Lesson 5: What Makes an Electromagnet?

Objective

• By the end of this lesson you should know what an electromagnet is and how to make one.

Comprehension

Vocabulary

• Magnet – an object that attracts iron and some other materials

• Electromagnet – a magnet that has coils of current-carrying wire around an iron core

Electromagnet

• Electromagnet – a magnet that has coils of current carrying wire around an iron core

• Essentially a magnet that runs on electricity

Magnetic Field

• A magnetic field is the space around a magnet where the magnetic force works

Electromagnet

• It is a temporary magnet– If you turn the electricity off, it no longer works

• How is an electromagnet different from a regular magnet?

Electromagnet Magnet

Electromagnet Uses

• Electromagnets are used in telephones, doorbells, construction equipment, and more

Electromagnet in Use

Electromagnet in Use

Electromagnet Strength

• You can make an electromagnet stronger in two ways:– Add more coils of wire– Add a greater power source

Comprehension Closure

• What is an electromagnet?

• What makes an electromagnet better than a regular magnet?

Exploration

Table Exploration: Make an Electromagnet

• Each table will be its own station.

• You will have about 15 minutes to do the exploration.

• Materials:– 3 pieces of wire (1 m, 1.5 m, and 2 m)– Iron nail– Battery– Paper clips

Make an Electromagnet*Copy this chart into your journals

Length of the Wire

Number of Coils Number of Paper Clips Lifted

1 meter

1.5 meters

2 meters

Step One Observations:

Make an ElectromagnetSteps:1. Hold the nail over the paper clips. Record what happens in your

journal under step one observations.2. Wrap the 1 meter wire (shortest) around the nail as many times as

you can leaving about 5 inches free on each end.3. Connect the ends of the wires to the battery and hold the nail over

the paper clips.4. Lift the nail out of the paper clips.5. Record your observations.6. Repeat steps 2-4 for the 1.5 meters wire (middle length). Record

your observations.7. Repeat steps 2-4 for the 2 meters wire (longest). Record your

observations.8. Answer the questions in your journal.

Make an Electromagnet

Answer the following questions in your journal by restating the question in your answer:

1. What happened to the nail after you wrapped the wire around it an attached it to the battery?

2. How does the number of coils relate to the electromagnet’s strength? How do you know this?

3. What makes an electromagnet different from a regular magnet?

Exploration Closure

• How can you make an electromagnet?