Which type of alternator consists of a rotating magnetic field and a single set of stator coils?

The type of alternator that consists of a rotating magnetic field and a single set of stator coils is indeed the single-phase alternator. In a single-phase alternator, the stator has one set of coils, which produces an alternating current (AC) that varies sinusoidally. This simplicity in design allows for the effective conversion of mechanical energy into electrical energy through electromagnetic induction, using a rotating magnetic field generated by either permanent magnets or electromagnets.

In contrast to single-phase alternators, three-phase alternators have three sets of coils that are arranged to produce three separate alternating currents, which are out of phase with each other. This configuration allows for a more efficient power generation and transmission but is more complex. Similarly, multi-phase and dual-phase designs involve multiple sets of coils that generate more than one current, increasing the complexity of the system. Thus, the defining characteristic of a single-phase alternator is its single set of stator coils, which distinguishes it from other configurations.