An out-of-phase condition between current and voltage in an eddy current coil can exist in which of the following?

An out-of-phase condition between current and voltage in an eddy current coil can exist in both the primary and secondary windings because each winding can experience different impedance characteristics depending on the materials and geometries involved.

In an eddy current testing system, the primary winding generates an alternating magnetic field when an alternating current flows through it. This magnetic field induces eddy currents in the conductive test specimen placed near or within this field. The secondary winding then detects these induced currents, and the interaction between the currents in the coil and the induced eddy currents in the specimen can cause phase shifts.

These shifts occur due to the resistive and reactive components of both the primary and secondary circuits. If the impedance in either the primary winding (which is affected by the applied voltage and current) or the secondary winding (which is influenced by the eddy currents generated in the test specimen) changes, it can lead to a situation where the voltage and current are no longer in phase. This concept is paramount in eddy current testing, as it helps in analyzing the properties of the test specimen and identifying any flaws or changes in material properties.

Thus, the presence of an out-of-phase condition in both the primary and secondary windings reflects how these components work together