Science/Strand IV/Content Standard 1/High School/Benchmark 5
Benchmark Question: How do electricity and magnetism
interact with matter?
Focus Question: How can electric currents be
produced by interacting wires and magnets?
Following a class discussion
about how an electrical current is produced, the teacher will perform the
following demonstration and introduce the concept of a magnetic field
producing an electric current:
1. Wrap 0.5 m of wire around a compass (top to bottom).
2. Attach the loose ends of the wire to a dry cell
(battery) and observe the needle in the compass.
3. Discuss that the needle moves because electricity is
moving through the wire and creates a magnetic field that interacts with
4. Make a coil of wire by wrapping approximately two m
of wire several times around a plastic bottle with the top and bottom
5. Remove the dry cell from the ends of the wire around
the compass, then twist these ends together with each of the exposed ends
of the two m of wire coil around the bottle.
See Compass Galvanometer Diagram below:
6. Place this setup on an overhead projector to project
onto a screen.
7. Take a bar magnet and quickly pass it back and forth
through the center of the bottle with the coil; observe the compass needle.
8. Have students pair up, discuss, and then create a
written description of what they think is happening.
9. Have students share their ideas with the class and
debate which pairs have the most accurate ideas.