Final answer:
In the context of a phase-to-phase transformer, the number of primary bushings corresponds to the number of phases, which is usually two for single-phase and three for three-phase transformers. The turns ratio can be equal or different, affecting the voltage transformation.
Step-by-step explanation:
In electrical engineering, particularly in the context of transformers, a phase-to-phase transformer refers to a type of transformer where the primary and secondary windings are connected between two phases. The number of primary bushings on a phase-to-phase transformer corresponds to the number of primary connections it has, which is typically two for a single-phase transformer (one for each phase) and three for a three-phase transformer (one for each phase). When referring to the turns of a transformer, it is important to understand that the ratio of primary to secondary turns determines the voltage transformation ratio of the transformer. This can be equal, or it can vary, meaning the transformer can have an equal number of primary and secondary turns (turns ratio of 1:1), or it can have more or fewer primary turns compared to secondary turns, resulting in step-up or step-down voltage transformation.