What is the term for the pattern created by iron powder on paper placed over a bar magnet?

The term for the pattern created by iron powder on paper placed over a bar magnet is a magnetograph. When iron filings or powder are sprinkled over a surface with a magnet underneath, they align themselves along the magnetic field lines, creating a visual representation of the field. This phenomenon effectively illustrates the distribution of magnetic forces around the magnet, making it a useful tool in studying magnetic fields.

Understanding the specific terminology is important for effective communication in the field of magnetic particle inspection and other applications involving magnetism. Magnetography has practical uses in various scientific and engineering contexts. While the other choices refer to different concepts related to magnetic fields or measurement, they do not describe the visual representation produced by iron powder, which is specifically referred to as a magnetograph.