Nate Electrical Practice Exam 2025 – 400 Free Practice Questions to Pass the Exam

Synchronous motors are characterized by their ability to run at a constant speed, which is locked to the frequency of the power supply. This means that the rotor moves in synchrony with the stator's rotating magnetic field, achieving a speed that is determined by the supply frequency and the number of poles in the motor. This constant speed operation is crucial for applications where precise control of the motor speed is vital.

In contrast, asynchronous motors, often referred to as induction motors, do not maintain a constant speed relative to the supply frequency. They operate with a slip between the rotor speed and the magnetic field speed, allowing for variations in their operating speed under different loads. This fundamental difference in operation leads to distinct applications for each type of motor, where synchronous motors are preferred in situations that require stable and predictable speeds.

The other options involve concepts that do not accurately identify the core characteristics of synchronous motors in comparison to asynchronous motors, making "synchronous motors operate at a constant speed" the best distinguishing factor.