Which of the following best describes a relay in motor control?

A relay in motor control serves a critical function by acting as a control mechanism that opens and closes circuits. This is essential because relays allow a low-power control signal to manage a higher power circuit, effectively enabling the operation of larger motors without requiring direct manual control of high power. When the control signal is applied, the relay's internal contacts will change state, either allowing current to flow through the motor circuit or interrupting that flow, thus turning the motor on or off as needed.

Relays can also provide additional safety features, such as isolation from the high-power circuits and protection against overcurrent conditions. Their use is common in motor control applications where automation and remote control of motors are necessary, underscoring the significance of their role in modern control systems.