IRON FILINGS
Iron filings arrange around a U-shaped magnet because of the magnetic field generated by the magnet. The magnetic field creates invisible lines of force that extend out from the north pole of the magnet to the south pole. The iron filings align themselves along these lines of force, which form a pattern that is often described as "field lines." The U-shaped magnet has two poles, north and south, and the field lines extend from the north pole to the south pole, passing through the center of the U-shape. The filings align along these lines of force, forming a pattern that is often described as "field lines". As the filings come in contact with the magnetic field, they align in a pattern that is determined by the strength and direction of the magnetic field.
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