Electromagnetics

Electromagnets

Electricity and Magnets are connected in a special way. In physics, we say the fields are "unified." Here we will build some circuits and observe the connections between electricity and magnetism.

Experiment with Compass and Electricity

Review, what is a compass needle, what makes it point in a particular direction.

a homemade compass points north

Use the electrical current to move the needle.

electric current and compass

This image shows what happens when there is no current in the wire. Push the button and see what happens:

electric current and compass

Why did the compass needle move?

It is a magnet that moves the compass so ... electrical current creates a magnetic field.

Try the same but with the compass need under the black wire. Is the result the same, similar or different. Why?

Electromagnet

The magnetic field produced by a current in a wire can be increased by adding many turned of a wire. A magnetic material such as iron in a steel screw will help to direct the magnetic field making the magnet "stronger"

electromagnet prototype board

Activity

What happens if the electromagnet is lifting several metal pieces (screws or paperclips) and the current is turned off?

STEM Education Standards

  • STEM Science StandardElectrical Energy
    Recognize that magnets have poles that attract and repel. Explain how a compass works. Demonstrate that current in a wire produces a magnetic field.
  • STEM Engineering StandardMaterials, and procedures
    Through building an electromagnet students will identify the proper materials and tools to complete a project following a procedure.