What does the "primary" side of a transformer refer to?

The designation of the "primary" side of a transformer refers specifically to the winding that supplies voltage to the transformer. In the operation of a transformer, the primary winding is connected to the incoming electrical power source, where it receives the alternating current (AC) voltage. This voltage creates a magnetic field that induces a voltage in the secondary winding.

Understanding this concept is crucial for comprehending how transformers function. The role of the primary winding is to take the provided voltage and use it to generate a magnetic flux, which is necessary for the transformer’s operation. The connections and the nature of the primary and secondary sides are what differentiate them; hence, the statement about the primary side is accurate in identifying it as the source of voltage to the transformer.