**PURPOSE: **To model the geometry for the magnetic field along the axis of a ring of current.

**DESCRIPTION: **This is three-dimensional visual model of the magnetic field of a ring of current. Vector current elements on opposite sides of the ring of current are shown along with vectors extending from the current elements to the point on the axis at which the magnetic field is to be determined. The two magnetic field vectors created by the two elements of current are perpendicular to both the current elements and to the radius vectors. The radial components of the vectors cancel, but the two axial vector components add, forming the net axial field vector shown in the model.

**SUGGESTIONS: **

**REFERENCES: ** (PIRA unknown.)

**EQUIPMENT: **Magnetic field of ring of current model.

**SETUP TIME: **None.