Wound-rotor motors are primarily used in applications requiring what characteristics?

Wound-rotor motors are especially valued for their ability to provide high starting torque while allowing for lower starting current, making them ideal for heavy-load applications. The design of these motors incorporates windings on the rotor that can be connected through external resistances, enabling better control over the motor's performance during startup.

When starting an application that requires significant torque—such as heavy machinery or pumps—wound-rotor motors can effectively meet that need without overwhelming the electrical supply with excessive current. The addition of external resistors allows the operator to adjust the rotor resistance, thus optimizing torque and managing current draw during startup. This characteristic is crucial in situations where high loads are involved, as it reduces the risk of damaging both the motor and the connected electrical infrastructure due to high inrush currents.

In contrast, while options referring to high starting current, low noise operation, or high efficiency may be relevant to certain motor applications, they do not capture the unique benefits that wound-rotor motors provide in terms of starting torque and current management.