What term describes a control system that adjusts its behavior based on measuring its output?

• A. Closed Loop System
• B. Single Circuit
• C. User Interface
• D. Flow Control Valves

Answer: (A)

Measuring the output and using that information to adjust how the system behaves is feedback control, realized as a closed-loop system. In a closed-loop setup, the actual output is continuously monitored and compared to a desired target. The difference (error) guides adjustments to the input, so the system can correct itself and maintain the intended performance despite disturbances. That ongoing measurement-and-adjustment is what makes it a closed-loop control.

The other ideas describe different things: a single circuit implies a one-way signal path without feedback; a user interface is about human–machine interaction rather than automatic control; flow control valves are components that regulate flow but don’t by themselves define a feedback-controlled system.