Master Feedback Control Systems: Quizzes and Practice Tests

Question 1

Which of the following is a drawback of using state-space methods in control system analysis and design?

Accepted Answer

Requires advanced mathematical knowledge

Answer

Provides a structured approach to modeling and analyzing systems

Answer

Enables the analysis of systems with nonlinearities

Answer

Simplifies controller design through pole placement

Question 2

Within a PID controller, the integral term serves primarily to:

Accepted Answer

Reduce steady-state errors

Answer

Enhance system stability

Answer

Accelerate response time

Answer

Prevent overshoot

Question 3

State-space representation of a system offers what key advantage?

Accepted Answer

A complete mathematical model of system dynamics

Answer

A visual depiction of system behavior over time

Answer

A detailed physical description of system components

Answer

A real-time simulation of system operation

Question 4

Which of the following is NOT a recognized type of feedback control system?

Accepted Answer

Open-loop control

Answer

Negative feedback

Answer

Positive feedback

Answer

Closed-loop control with state feedback

Question 5

In a mechatronic system, sensors primarily serve the purpose of:

Accepted Answer

Providing feedback on system state

Answer

Generating control inputs for actuators

Answer

Supplying power to system components

Answer

Providing mechanical support for system parts

Question 6

Which of the following is a widely used feedback controller in mechatronic systems?

Accepted Answer

PID controller

Answer

State-space controller

Answer

On-off controller

Answer

Adaptive controller

Question 7

What is the fundamental objective of a feedback control system?

Accepted Answer

Maintain desired system output despite disturbances or uncertainties

Answer

Enhance input signal strength

Answer

Suppress noise and unwanted signals in the system

Answer

Generate control signals directly for actuators

Question 8

Which of the following applications does NOT typically utilize feedback control systems in mechatronics?

Accepted Answer

Data analysis

Answer

Industrial automation

Answer

Robotics

Answer

Automotive engineering

Question 9

What is the primary function of the state-space representation in feedback control system analysis?

Accepted Answer

Describe system dynamics in terms of state variables

Answer

Simplify the design process of feedback controllers

Answer

Assess system stability

Answer

Predict system response through simulations

Question 10

What is the primary purpose of the integral term in a PID controller?

Accepted Answer

Eliminate steady-state error

Answer

Reduce overshoot

Answer

Increase controller gain

Answer

Dampen system oscillations

Question 11

Which of the following is NOT a potential limitation of feedback control systems?

Accepted Answer

Guaranteed perfect regulation

Answer

Time delays

Answer

Sensitivity to noise

Answer

Actuator saturation

Question 12

What is the fundamental distinction between open-loop and closed-loop control systems?

Accepted Answer

Closed-loop systems utilize feedback, whereas open-loop systems do not.

Answer

Open-loop systems utilize feedback, whereas closed-loop systems do not.

Answer

Open-loop systems are inherently more accurate than closed-loop systems.

Answer

Closed-loop systems are inherently faster than open-loop systems.

Question 13

In a PID controller, the 'I' term is responsible for:

Accepted Answer

Integral action

Answer

Proportional gain

Answer

Derivative action

Answer

Lag compensation

Question 14

A type 1 feedback control system has a closed-loop transfer function with a numerator degree that is:

Accepted Answer

Less than the denominator degree

Answer

Equal to the denominator degree

Answer

Greater than the denominator degree

Answer

Zero

Question 15

A feedback control system is considered marginally stable when:

Accepted Answer

Its closed-loop poles have zero real part

Answer

Its closed-loop poles have imaginary part other than zero

Answer

Its closed-loop poles have positive real part

Answer

Its closed-loop poles have complex values with nonzero real part

Question 16

Given a PID controller with P = 10, I = 0.5, and D = 2, calculate the controller's gain when the Laplace transform of the input r(s) is set to zero.

Accepted Answer

10

Answer

12

Answer

15

Answer

20

Question 17

In a control system, what is the primary function of feedback?

Accepted Answer

Reduces the system's sensitivity to external disturbances

Answer

Increases the system's gain

Answer

Always makes the system unstable

Answer

Feedback is not necessary in control systems

Question 18

How does sensor noise affect feedback control systems? Discuss its causes, types, and suggest ways to minimize its impact.

Accepted Answer

Electrical noise can be reduced by grounding components and using shielded cables.

Accepted Answer

Mechanical noise can be minimized using vibration isolators.

Answer

Sensor noise always negatively affects control system performance.

Answer

Sensor noise can be ignored if it falls below a certain threshold.

Question 19

In the design of feedback control systems, which three primary factors must engineers carefully consider and balance?

Accepted Answer

Performance, robustness, and cost

Answer

Accuracy, reliability, and efficiency

Answer

Speed, stability, and sensitivity

Answer

Simplicity, maintainability, and testability

Question 20

In a negative feedback control system, the output is:

Accepted Answer

Subtracted from the input to reduce the error

Answer

Added to the input to amplify it

Answer

Multiplied by the input to enhance its effect

Answer

Divided by the input to create a ratio

Question 21

Which of the following is NOT a constituent part of a PID controller?

Accepted Answer

Differential

Answer

Proportional

Answer

Derivative

Answer

Integral

Question 22

In state-space representation, the state vector encompasses:

Accepted Answer

The minimum number of variables necessary to describe the system's behavior

Answer

The system's inputs and outputs exclusively

Answer

All possible system state combinations

Answer

The system's transfer function coefficients

Question 23

The transfer function of a system represents:

Accepted Answer

The ratio of the output's Laplace transform to the input's Laplace transform

Answer

The time-domain response of the system to a specific input

Answer

The frequency response characteristics of the system

Answer

The stability criteria for the system

Question 24

The primary objective of a proportional controller is to:

Accepted Answer

Minimize steady-state error, reducing the difference between actual and desired output

Answer

Accelerate system response, achieving faster output changes

Answer

Enhance system stability, preventing oscillations and instability

Answer

Eliminate overshoot, preventing excessive output values

Question 25

In a closed-loop control system, the feedback signal:

Accepted Answer

Is compared to the reference input to determine the error

Answer

Is directly used to control the system's output

Answer

Is amplified before being compared to the reference input

Answer

Is ignored as it has no impact on system behavior

Question 26

The bandwidth of a control system is:

Accepted Answer

The range of frequencies over which the system maintains satisfactory performance

Answer

The upper limit of frequencies beyond which the system becomes unstable

Answer

The frequency at which the system's output and input have equal magnitudes

Answer

The最低可操作频率

Question 27

A defining characteristic of a stable control system is:

Accepted Answer

Bounded output for bounded input, ensuring system stability under various operating conditions

Answer

Unbounded output for bounded input, indicating potential system instability

Answer

Zero steady-state error for all inputs, regardless of system dynamics

Answer

Fast response time, enabling rapid system adjustments

Question 28

Identify the feedback control system that does not rely on a feedback signal.

Accepted Answer

Open-loop system

Answer

Closed-loop system

Answer

Negative feedback system

Answer

Positive feedback system

Question 29

What is the primary goal of employing a proportional-integral-derivative (PID) controller in a feedback control system?

Accepted Answer

To minimize steady-state error and enhance the system's response time.

Answer

To augment the system's gain

Answer

To eradicate oscillations in the system

Question 30

Which of the following disadvantages is associated with the use of state-space methods for analyzing control systems?

Accepted Answer

They can be computationally demanding and complex to employ.

Answer

They fail to provide valuable insights into system behavior.

Answer

They are unsuitable for real-time control applications.

Answer

They are applicable exclusively to linear systems.

Question 31

Determine the transfer function, H(s), of a system characterized by its impulse response, h(t).

Accepted Answer

H(s) = ∫[0→∞]h(t)e^(−st)dt

Answer

H(s) = ∂[0→∞]h(t)/dt

Answer

H(s) = h(t)s

Answer

H(s) = 1/h(t)

Question 32

Describe the effect of using a lead compensator in a control system.

Accepted Answer

It increases the phase margin while decreasing the gain.

Answer

It reduces the gain while increasing the phase margin.

Answer

It has no effect on the phase margin or gain.

Answer

It increases the gain while decreasing the phase margin.

Question 33

Which of the following methods is used for designing state feedback controllers?

Accepted Answer

Pole placement

Answer

Frequency response method

Answer

Nyquist criterion

Answer

Root locus method

Question 34

State the primary advantage of using Kalman filtering in feedback control systems.

Accepted Answer

It allows for the estimation of the system state even with noisy measurements.

Answer

It is straightforward to implement.

Answer

It ensures optimal control performance.

Question 35

What is the function of a reference input in a feedback control system?

Accepted Answer

It specifies the desired output response of the system.

Answer

It compensates for external disturbances that affect the system.

Answer

It provides feedback information to the controller.

Answer

It stabilizes the system and prevents oscillations.

Question 36

The primary goal of a feedback control system is to:

Accepted Answer

Maintain a desired state despite disturbances

Answer

Minimize energy consumption

Answer

Maximize efficiency

Question 37

In a stable feedback control system, which type of feedback is used?

Accepted Answer

Negative feedback

Answer

Positive feedback

Answer

Open-loop design

Answer

Unbounded gain

Question 38

Which sensor is commonly used to measure angular displacement in mechatronic systems?

Accepted Answer

Encoder

Answer

Strain gauge

Answer

Thermocouple

Answer

Accelerometer

Question 39

For systems with significant time delays, which control strategy is most suitable?

Accepted Answer

Smith Predictor

Answer

State feedback

Answer

PID control

Answer

Proportional control

Question 40

The transfer function of a first-order low-pass filter is:

Accepted Answer

1/(s+a)

Answer

a/(s+a)

Answer

1/(a+s)

Answer

s/(s+a)

Question 41

The primary purpose of the Nyquist stability criterion is to:

Accepted Answer

Determine stability of closed-loop systems using frequency response

Answer

Calculate system bandwidth

Answer

Optimize PID parameters

Question 42

In a closed-loop feedback control system, what is the role of negative feedback?

Accepted Answer

To reduce the error between the desired and actual output

Answer

To create oscillations in the system

Answer

To amplify the error between the desired and actual output

Question 43

Which of the following is NOT a type of PID controller?

Accepted Answer

Proportional-Integral-Differential-Derivative (PIDD)

Answer

Proportional-Derivative (PD)

Answer

Proportional-Integral (PI)

Question 44

What is the transfer function form of an ideal proportional controller?

Accepted Answer

Kp

Answer

Ki

Answer

Kd

Answer

1/Kp

Question 45

Which of the following is **not** a disadvantage of using state-space methods in control system design?

Accepted Answer

Easy to implement in real-time

Answer

Can be computationally expensive for high-order systems

Answer

Requires a complete mathematical model of the system

Question 46

What is the primary purpose of a Kalman filter in control systems?

Accepted Answer

To estimate the state of a system from noisy measurements

Answer

To analyze the stability of a system

Answer

To design optimal control laws

Question 47

Which of the following is a widely used stability criterion for a linear time-invariant (LTI) system?

Accepted Answer

Routh-Hurwitz criterion

Answer

Nyquist criterion

Answer

Shannon criterion

Answer

Bode criterion

Question 48

What is the key difference between open-loop and closed-loop control systems?

Accepted Answer

In open-loop systems, the output does not affect the input, while in closed-loop systems, the output is fed back to affect the input.

Answer

Open-loop systems are more stable than closed-loop systems.

Question 49

Which of the following is a significant benefit of using feedback in control systems?

Accepted Answer

Improved accuracy and disturbance rejection

Answer

Reduced stability

Answer

Increased system complexity

Answer

Higher power consumption

Question 50

What is the definition of the time constant of a first-order system?

Accepted Answer

The time taken for the output to reach 63.2% of its final value

Answer

The time taken for the output to reach 99% of its final value

Answer

The time taken for the output to reach 50% of its final value