What statement is TRUE concerning the speed of a synchronous ac propulsion motor?

Correct Answer: Option A — The speed is directly proportional to the frequency applied to its stator windings.

Synchronous motor speed is governed by the formula N = 120f/P, where N is speed, f is frequency, and P is the number of poles. Therefore, the speed is directly proportional to the frequency applied to the stator windings, which establishes the rotating magnetic field that the rotor field poles must follow.