If shrunken down to micron size, a compass needle could wobble. (Courtesy: iStockphoto/tobias machhaus) A tiny magnetic needle just 10 μm long could be used to create a magnetic-field sensor that – if ...

A magnetic field is invisible, but it can be detected using a magnetic compass. A compass contains a small bar magnet on a pivot so that it can rotate. The compass needle points in the direction of ...

A compass is a navigational tool that helps people find their direction using the earth's magnetic field. It contains a magnet that aligns itself with the earth's north pole to indicate the direction.

A compass needle is essentially a thin bar magnet. If it were free to move in all three dimensions, a magnet would line up along any local magnetic field line. Field lines are graphical ...