Abstract
By using four magnets and five electromagnets, we showed that there is a good linear correlation between the values of magnet flux density of each N pole measured with a magnetic flux meter and those of DC obtained with a clamp meter. Thus, the magnetic flux density of a magnet can be measured with a clamp meter. The differences of magnetic flux density at each distance from N pole of alnico magnets also agree well with those of current measured with a clamp meter. Our experiment was applied with second grade students of a public junior high school in Nagano Prefecture to investigate the magnetic flux density of a magnet using a clamp meter. It was found that students could measure the magnetic flux density, that they were satisfied with the present study and that most students have true recognition of the nature of a magnet. They also thought that a clamp meter is a useful teaching tool for the study of a magnet.
