Which type of motor construction feature is specific to Wound Rotor Motors?

Wound Rotor Motors are specifically characterized by the presence of slip rings. This feature is integral to their operation, as slip rings allow for the connection of external resistances to the rotor circuit. This enables the adjustment of rotor resistance, which can enhance the motor's performance, particularly during startup and under varying load conditions.

When the rotor has a wound configuration, the windings are connected to the slip rings, which facilitate the passage of current in a manner that allows the rotor to generate a magnetic field. The use of slip rings distinguishes wound rotor motors from other motor types, such as squirrel cage motors, which do not utilize this feature.

Integrating a microprocessor, employing permanent magnets, and utilizing a commutator are all characteristics associated with different types of motors and are not relevant to the unique features of wound rotor motors. Therefore, the presence of slip rings is the defining construction feature for this type of motor.