Error detector
Final control element
Sensor
Oscillator
Answer is Wrong!
Answer is Right!
The correct answer is D. Oscillator.
An oscillator is a device that produces a continuous, periodic signal. It is not used in an automatic control system because it does not provide any feedback or control. The other three options (A, B, and C) are all essential elements of an automatic control system.
- A sensor is a device that detects a physical quantity and converts it into a signal that can be read by a control system.
- A final control element is a device that changes the process variable in response to a signal from the controller.
- A controller is a device that compares the measured process variable to a desired setpoint and generates a signal to the final control element to correct any deviation.
In an automatic control system, the sensor detects the current value of the process variable, the controller compares this value to the desired setpoint, and the final control element changes the process variable to bring it closer to the setpoint. The oscillator is not used in this process because it does not provide any feedback or control.