ACTIVITY: Electromagnets
EQ: How can you make an electromagnet stronger?
BACKGROUND INFORMATION: In 1820 Hans Oersted showed that current carrying wires generate a magnetic field. His
discovery lead to power generation and the many electrical devices we have today. William Sturgeon developed the first
electromagnet. He used it to lift heavy iron materials. An electromagnet has a soft iron core encased in wound wire.
When current passes through the wire, the device acts like a magnet. Today, devices that use electromagnets are circuit
breakers, MRI machines, and doorbells. Sometimes you use the word solenoid for an electromagnet. Michael Faraday
moved a magnet through a coil of wire and detected a small current. Faraday, along with similar experiments by Joseph
Henry, made possible the development of electric generators and transformers that provide most of the electricity in
the world.
RESULTS:
PART 1 Oersted’s Experiments
Compass Placement
At right angles to the wire
Parallel to the wire
Parallel to the wire with the current reversed
Part 2: An Electromagnet
Picture of Setup
Compass next to a coil of wire
Compass next to a coil of wire
with a battery and a switch
Compass next to a coil of wire
wound around a nail with a
battery and a switch
Observation
The compass needle does not deflect
The compass needle deflects away from the wire
The compass needle deflects toward the wire
Observations
Nothing happens, the compass needle does not deflect
The compass needle deflects slightly
The compass needle deflects
What proof do you have that the device is an electromagnet? The device picked up 4 paper clips.
Design two experiments to increase the strength of the electromagnet you made above.
EXPERIMENT 1
Hypothesis:
Procedure:
Results:
Conclusion:
EXPERIMENT 2
Hypothesis:
Procedure:
Results:
Conclusion:
THINKING ABOUT WHAT YOU OBSERVED:
1. What relationship exists between the direction of the current in the wire and the needle deflection?
2. What are three ways to make an electromagnet stronger?
3. What parts of the electromagnet are most attractive?
4. Describe the strongest electromagnet you made. What proof do you have?