Hall Effect Probe
Measure the Magnetic Fields that You Teach
The magnetic field created by the current in a long straight wire is the standard application of Ampere's Law. The axial magnetic field of a current loop is often the textbook's example of the Biot-Savart Law. The 1/r3 dependence of the field of a magnetic dipole and the uniformity of the axial field in a Helmholtz pair are other examples that can be found in the problem section of many texts.
The Hall Effect Probe makes measurements of these "textbook" fields possible and affordable.