Grade 8-Electromagnetism (Lab activity on Tuesday, March 24th 2009)

ELECTROMAGNETISM

Oersted's Experiment
In 1819, a Danish scientist named Hans Christian Oersted discovered a close relationship between electricity and magnetism with this experiment. Oersted's discovery led to the study of electromagnetism. Try Oersted's experiment yourself!


Materials You Will Need:
- Two batteries (size D)
· - Small, non-metallic bowl
· - Needle
· - Modeling clay
· - Switch (you can make the switch from paper clips)
· - Tape (cellotape)
·
Steps to Create Oersted's Experiment:
-Stroke needle 50 times from center to one end with
magnet. Tape on cork and place in bowl of water.
- Watch direction of needle when you move magnet n near it.
- Place wire over top of dish. Secure it with clay.
- Connect one end of wire to switch.
- Connect other wire end from switch to negative (-)
lead of your batteries.
- Connect other wire end from bowl to positive (+) lead
of your batteries.

- Close switch. Observe results.

You've done the experiment that Oersted did— and have shown that there's a magnetic field around the circuit wire when the electric current is flowing. When the current flows, the magnetic needle is deflected at right angles to the circuit wire.

This experiment is one of the most important in the utilization of electric power—it led to the discovery of electromagnetism and the development of the electric motor.