A basic electric control circuit has how many major pieces?

A basic electric control circuit is fundamentally structured around several key components that work together to monitor and control a specific process or system. The correct choice highlights the essential elements that make up this circuit: the sensor switch and the final control element.

The sensor switch is responsible for detecting the current state of the system, such as temperature, pressure, or flow, and it sends this information to the controller. This data is crucial for the controller to determine whether any adjustments need to be made to maintain the desired conditions.

The final control element, which may include devices like actuators or control valves, carries out the necessary changes dictated by the control system. It acts on the signal from the controller to regulate the system, ensuring that it operates within the desired parameters.

Together, the sensor switch and final control element form a feedback loop that enables the system to function effectively. The controller processes sensor data and commands the final control element to adjust as necessary, maintaining stability and efficient operation.

In the context of the other choices, while they suggest different components that may be relevant in control systems, they do not accurately capture the fundamental pairing that characterizes a basic electric control circuit as effectively as the combination of the sensor switch and the final control element does.