Which of the following is not a component of a transformer?

A transformer consists of several key components that facilitate its operation of transferring electrical energy between circuits. The core, which is composed of magnetic material, serves to channel the magnetic field created by the alternating current in the windings.

Windings, typically made of copper or aluminum wire, are essential for the transformer, as they are the coils where electrical energy is transformed from one voltage level to another through electromagnetic induction. Insulation is also critical as it prevents electrical shorts and protects the windings from environmental factors, ensuring the transformer's reliability and safety.

In contrast, the term "electrical coupling" may refer generally to how electrical circuits interact but is not a specific component of a transformer. While transformers operate based on the coupling between the primary and secondary windings, "electrical coupling" itself doesn't represent a distinct physical part of the transformer. This distinction clarifies why it is not considered a component of a transformer.