Nate Electrical Practice Exam

Which of the following devices is used to maintain a consistent motor operation?

1. Capacitor

2. Contactor

3. Relay

4. Resistor

The correct answer is: Contactor

The device that is primarily used to maintain consistent motor operation is a contactor. A contactor is an electrically controlled switch that is designed to manage the power supply to a motor. It ensures that the motor receives adequate power while protecting it from overloads and faults. When a contactor is engaged, it closes the circuit to the motor, allowing it to operate continuously under the designed conditions. Contactors have various current ratings and features, including built-in overload protection, making them suitable for starting and stopping motors reliably. Their construction enables them to handle higher currents, which is essential for motor applications. By using a contactor, operators can efficiently control motor operations, enhancing reliability and performance. In contrast to contactors, capacitors are used primarily for power factor correction and to improve starting torque in single-phase motors, rather than for direct control of motor operation. Relays are generally used for signaling and low-power control applications rather than for managing high-power motor operations. Resistors can be used to limit current or for speed control, but they do not maintain motor operation in the sense of keeping it consistently running under various load conditions.