Science Experiments Using Electromagnets for Middle School & High School

Use batteries to create fascinating magnetic experiments.

Electromagnets are metal elements that are magnetized using electricity. This type of magnet is useful when there is no need for a permanent magnetic presence, such as in automobiles. Middle and high school students can create elaborate demonstrations of electromagnetic power to showcase their understanding of how we use electromagnets in everyday life.

Strength of the Magnet

Create several electromagnets, each using different supplies. In one, use a single battery and a short coil of wire; in another, use multiple batteries and a longer coil of wire. As another variation, use batteries of different strengths, such as AAA batteries and D cells. The experiment demonstrates the different strengths of the magnets based on the variables of their construction. Select different-size pieces of metal for the magnets to attract, including some that are too heavy for the smallest electromagnet to pick up.

Projectile Ring

Demonstrate Lenz's Law, which describes the direction of flow for induced currents, with a projectile ring project using electromagnets. Construct an electromagnet using a large bolt. Cover the bolt with a copper tube or ring. Once charged, the tube will shoot off the bolt and into the air. The bolt can be charged using the push of a button or by manually connecting the wire to the battery. Two electromagnets built in this manner can be connected with a wire across the top to propel the ring back and forth between them.

Solenoids

Demonstrate how parts of an automobile or doorbells use electromagnets by creating a solenoid. A solenoid uses an electromagnet to pull a metal rod into the core. When the coil is electrified and the rod is pulled into the core, it engages other parts to create a reaction. For the car, the reaction is to start the car. For the doorbell, the reaction is to send the signal and create the sound that is heard inside the house.

Create Sound Waves

Construct a speaker using a film canister, magnetic wire and a permanent magnet. The magnetic wire will become the electromagnet in the experiment. Secure the permanent magnet to the bottom of the film canister and wrap the wire around the base of the canister. Once the parts are assembled, connect them to a low-powered radio. Follow all safety precautions for connecting the wires so you don't damage the radio. Turn on the radio and you will be able to hear sounds coming from the speaker.

References

• Science of the Brain; Electromagnets -- How Can Electricity Create a Magnet?; Marshall Brain
• Cool Magnet Man: Jumping Ring
• Cool Magnet Man: Solenoids
• Hila Science Camp: Electromagnetism

Resources

• Cool Magnet Man: DC Electromagnets
• Cool Magnet Man: AC Electromagnets