Which term describes the relationship between the primary and secondary coils in a transformer?

The term that describes the relationship between the primary and secondary coils in a transformer is coupling. In a transformer, the primary coil is connected to an input power source, and the secondary coil delivers the transformed voltage to an output load. The essential mechanism at play is magnetic coupling, where the alternating current in the primary coil creates a changing magnetic field that induces a voltage in the secondary coil through electromagnetic induction.

This coupling is key to the operation of the transformer, allowing energy to be transferred between the two coils without a direct electrical connection, effectively modifying the voltage and current levels according to the turns ratio of the coils. The efficiency of this energy transfer relies on the close physical arrangement of the coils, which maximizes the magnetic flux linkage between them. Hence, coupling accurately captures the nature of the interaction between the primary and secondary coils in a transformer.