Closed Loop

What is a closed-loop system?

• A system that does not use feedback

• A system that uses feedback control

• A system that is always unstable

• A system that only works with open loops

What does the closed-loop transfer function for setpoint changes refer to?

• Open loop transfer function

• Servo transfer function

• Regulator transfer function

• Feedback transfer function

What is the purpose of block diagram reduction?

• To complicate the system

• To simplify the system for analysis

• To eliminate feedback

• To increase the number of loops

What is the stability criterion for a closed-loop system?

• Only one root needs to be negative

• All roots must be positive

• Roots can be anywhere in the complex plane

• All roots must be negative or have negative real parts

What does the Routh stability test analyze?

• The coefficients of the characteristic equation

• The roots of the characteristic equation

• The input variables only

• The feedback gain only

What happens when the controller gain (Kc) is too high?

• The system becomes more stable

• The system becomes unstable

• The system has no effect

• The system always oscillates

What is the open loop transfer function?

• The feedback path only

• The product of all transfer functions in the loop

• The sum of all transfer functions

• The forward path only

What is the root locus diagram used for?

• To plot the roots of the characteristic equation

• To find the input variables

• To increase the feedback gain

• To eliminate the feedback loop

What does the term 'bounded input' refer to?

• An input that is always zero

• An input that is always negative

• An input that increases indefinitely

• An input that stays within limits

What is the characteristic equation for a closed-loop system?

• 1 + π_no > 0

• π_no = 0

• 1 - π_no = 0

• 1 + π_no = 0