PURPOSE: To visualize the magnetic field around a wire and near two wires carrying opposite currents.
DESCRIPTION: A large number of turns of small wire are used to produce a larger current, which passes through a plastic sheet on an overhead projector. Two current sources are available on this one: a single wire and two nearby wires with equal but opposite currents. Sprinkling iron filings on the plastic sheet near the wires and gently tapping the sheet causes the filings to line up along the magnetic field lines.
A heavy-duty 7.5 volt battery is used as the power source.
REFERENCES: (PIRA 5H15.10)
EQUIPMENT: Magnetic field of single wire/wire loop combination with 7.5 volt battery and iron filings on overhead projector.
SETUP TIME: None.
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