<p><strong>SF Fig. 7.5.</strong> The orientation of iron fillings makes the magnetic field lines around a bar magnet visible. Iron is a magnetic material that is either repelled or attracted to the two poles of the bar magnet.</p>

SF Fig. 7.5. The orientation of iron fillings makes the magnetic field lines around a bar magnet visible. Iron is a magnetic material that is either repelled or attracted to the two poles of the bar magnet.

Image courtesy of Dr. Dayna Mason, Flickr, modified by Narrissa Spies