Download Electromagnet activity page

Electromagnet
Age: 3rd grade and up; can be enjoyed by almost anyone!
Concepts: Electricity, Magnetism
Materials:
1 wire segment (about 3 feet)
1 metal bolt (not intrinsically magnetic)
1 D battery (more will increase the intensity of the magnet)
1 D battery holder (if you use more batteries, you will need more holders)
Lots of paper clips
Instructions:
1. Strip about one inch of the plastic coating off of each end of the wire (this should be
done by an adult).
2. Snap the battery into the holder, being careful to align the ends correctly. After the
activity is completed, feel free to return to this step and experiment with the number of
batteries used to see how this affects the strength of the electromagnet.
3. Leaving about 4 inches on either end, wrap the wire around the bolt as much as you
can. After the kids have finished building the electromagnet, feel free to return to this
step and experiment with different numbers of wraps and see how this affects the
strength of the electromagnet.
4. Bend the bare wire ends so that one is attached to each of the metal ends of the battery
holder.
5. Hold a paper clip next to the wrapped wire and watch it stick! Continue adding more
paper clips until they no longer stick and then record the number of clips your
electromagnet held. Compare your number with those of other students and see whose
electromagnet worked best.
6. For an extra activity, as hinted above, have the students unwrap their wires and record a
table with number of wraps and number of paper clips held. They can also keep the
number of wraps constant and try adding more batteries.
7. For another variation, try replacing the metal bolt with a wooden dowel or a plastic straw.
How it Works/Discussion Questions:
What seems to affect how strong the electromagnet is? Discuss how magnets
work and how a wire wrapped around certain materials creates an electromagnet. All
wires carrying current produce a magnetic field which is circular and perpendicular to the
wire. By wrapping the wire in loops, you align the small magnetic field lines so that they
point in the same direction, greatly amplifying the magnetic field produced. The bolt is
affected by this magnetic field; it is transformed into a temporary magnet.
http://science.howstuffworks.com/electromagnet4.htm