Be certain that magnets are not near the sensor during the iron bar portion of the activity.

If the initial magnetic field of the iron bar has the opposite polarity of the bar magnet, students may become confused. Coach them through the discussion, helping them to understand their results.

It is important to emphasize that physical contact between the bar magnet and iron bar is not necessary to temporarily magnetize the iron bar.

To download the Magnetic Fields DataStudio file with sample data for this experiment, click on a Windows (Zip file) or Macintosh (Stuffit file).