Either through a "hands-on" activity or a classroom demonstration, students will make a small motor to see the use of magnets.
- Home survey sheet for students
- 5 small disk magnets
- 2 large paper clips
- A Styrofoam cup
- A solid enameled or insulated 20-gauge copper wire (about 2 ft. long)
- A battery or power supply (2 or 3 D cells or a 6-volt lantern work best)
- 2 electrical lead wires with alligator clips at both ends (available at
- Wire stripper (if you used insulated wire); Sandpaper (if you used enameled
- A black, permanent marking pen
- A battery holder (if using D cells)
Magnetism by John Woodruff
Physics for Kids:49 Experiments with Electricity and Magnetism by Robert W.Wood
Science Projects about Electricity and Magnets by Robert Gardner
Background for Teachers
Electric motors are everywhere. In your house, nearly every mechanical movement that you
see around you is caused by an AC or DC electric motor. An electric motor is all about magnets and magnetism. These small motors use magnetism to create motion. Due to the fundamental law of all magnets that opposites attract and likes repel, these forces create rotational
motion inside an electric motor, thus producing the force that is necessary for driving the
machine attached to the motor.
Intended Learning Outcomes
4-Communicate effectively using science language and reasoning.
Invitation to Learn:
The day before the lesson is to be presented, give all students a magnet survey
sheet and have them look for magnets in use in their homes. Have them check
each room in the house looking for magnets. Don 't give them too much information
before sending them on the “search.” The next day, make a list on
the board or chart paper of all the places the students found magnets in use.
Tell the students that magnets are found in nearly every small appliance motor
(i.e. can openers, blow dryers, hand drills, etc.) Discuss other places they
might find magnets. Tell the students that they will be making a small motor
to see the use of the magnets. (This may also be done as a demonstration if
supplies are limited.)
- Wind the copper wire into a coil about 1 inch in diameter. Make four or
five loops. Wrap the ends of the wire around the coil a couple of times on
opposite sides to hold the coil together. Leave 2 inches of wire projecting
from each side of the coil and cut off any extra wire.
- If you are using insulated wire, strip the insulation off the ends of the
wire projecting from the coil. If you are using enameled wire, use the sandpaper
to remove the enamel. Color one of the projecting wire ends black on one side
with the marking pen. (If the coil is held in a vertical plane, color the
top half of one of the wires black.)
- Turn the cup upside down and place two magnets on top of it in the center.
Attach three more magnets inside the cup, directly beneath the original magnets.
This creates a stronger magnetic field and holds the top magnets in place.
- Unfold one end of each paper clip and tape them to opposite sides of the
cup, with their unfolded ends down. Rest the ends of the coil in the cradles
formed by the paper clips. (Make sure the end painted black is UP.) Adjust
the height of the clips so that when the coil spins, it clears the magnets
by about 1/16 inch. Adjust the coil and the clips until the coil stays balanced
and centered while spinning. Good balance is essential in getting the motor
to operate well.
- If you are using a battery, put it in a battery holder. Use the clip leads
to connect the battery or power source to the paper clips. Connect one terminal
of the battery to one paper clip and the other terminal to the other paper
- Give the coil a spin to start it turning. If it doesn't keep spinning on
its own, check to make sure the coil assembly is well balanced when spinning,
that the enamel has been thoroughly scraped off, that the projected end has
been painted black, and that the coils and magnets are close together, but
will not hit each other. You may have to adjust the distance of the cradles.
Keep making minor adjustments until the motor works. Patience will be rewarded.
Conclusion: Current flowing through the wire coil creates an electromagnet.
One face of the coil becomes a North pole, the other a South Pole. The permanent
magnet attracts its opposite pole on the coil and repels its like pole, causing
the coil to spin.
- Have the students return home with their magnet surveys and add to their
lists the many uses of magnets.
- Put the students in research teams and have them report on the way magnets
are used in such things as Maglev trains, doorbells, Magna Doodles, stereo
speakers, video and cassette tapes and transformers. Use the web site mentioned
below called “How Stuff Works ” as a great reference.
- The students will be able to name at least 10 common household items that
- The students, using a small motor diagram, will be able to tell how the
motor works and why it is capable of generating power.
This lesson is part of the Fifth Grade Science Teacher Resource Book (TRB3) http://www.usoe.org/curr/science/core/5th/TRB5/. The TRB3 is designed to be your textbook in teaching science curriculum to your students. This book covers all the objectives of each standard and benchmark. If taught efficiently, a student should do well on the End-of-Level (CRT) tests. The TRB3 is designed for teachers who know very little about science, as well as for teachers who have a broad understanding of science.