Control Systems Modelling and Analysis: Master the Fundamentals

Question 1

In control engineering, what is the primary function of the root locus technique?

Accepted Answer

Graphically analyzing a control system's stability by examining its poles' location in the complex plane.

Answer

Designing controllers to optimize system performance and stability.

Answer

Determining the system's transfer function and identifying its poles and zeros.

Answer

Calculating the system's frequency response and assessing its bandwidth and resonance characteristics.

Question 2

For a linear time-invariant system, which condition ensures its stability?

Accepted Answer

All poles lie in the left half of the s-plane.

Answer

At least one pole lies in the right half of the s-plane.

Answer

At least one pole lies on the imaginary axis of the s-plane.

Answer

The system has more poles than zeros.

Question 3

For a linear time-invariant (LTI) system to be controllable, which condition must be met?

Accepted Answer

The system has at least one input.

Answer

The system is stable.

Answer

The system has more inputs than outputs.

Answer

The system is minimum phase.

Question 4

In control systems, which method is specifically employed for frequency response analysis?

Accepted Answer

Bode plot

Answer

Root locus

Answer

Nyquist plot

Answer

Time response analysis

Question 5

In a causal linear time-invariant (LTI) system, how is the output signal related to the input signal?

Accepted Answer

The output signal is fully determined by the input signal and the system's impulse response.

Answer

The output signal can occur before the input signal.

Answer

The output signal is always smaller than the input signal.

Answer

The system's frequency response is independent of the input signal.

Question 6

Which of the following is a disadvantage of using state-space representation for control system analysis?

Accepted Answer

Makes it difficult to visualize the system's behavior.

Answer

Provides a systematic approach to derive controller and observer equations.

Answer

Facilitates the analysis of system stability using eigenvalue analysis.

Answer

Enables the design of compensators using pole placement techniques.

Question 7

Which method is used to determine the stability of a second-order system with the transfer function  H(s) = K / ((s + a)(s + b))?

Accepted Answer

Routh-Hurwitz criterion

Answer

Nyquist plot

Answer

Bode plot

Answer

Root locus

Question 8

Which method is NOT specifically used for designing controllers in linear control systems?

Accepted Answer

Fuzzy logic control

Answer

Bode plot analysis

Answer

Nyquist plot analysis

Answer

Root locus analysis

Question 9

Which condition is necessary for a system to be controllable?

Accepted Answer

The number of inputs equals or exceeds the number of states.

Answer

The system is observable.

Answer

The system is stable.

Answer

The system is linear.

Question 10

In control systems, which graphical method displays a system's stability in the complex plane?

Accepted Answer

Root locus analysis

Answer

Bode plot analysis

Question 11

Which characteristic is **incompatible** with stability in a control system?

Accepted Answer

Negative damping ratio

Answer

Bounded output for bounded input

Answer

Absence of overshoot in the step response

Answer

Existence of positive real roots in the characteristic equation

Question 12

In Nyquist stability analysis, what does it indicate about the stability of the closed-loop system if the Nyquist plot encircles the -1+0j point clockwise?

Accepted Answer

Unstable

Answer

Stable

Answer

Open-loop stable

Answer

Phase margin of 180 degrees

Question 13

When designing control software for a control system, which factor is crucial to consider?

Accepted Answer

Ensuring real-time performance and minimizing latency

Answer

Selecting the optimal programming language

Answer

Prioritizing code clarity and maintainability

Answer

Optimizing memory usage for efficient operation

Question 14

Which of the following is **not** a common characteristic of feedback control systems?

Accepted Answer

Reversibility

Answer

Stability

Answer

Precise output control

Answer

Responsiveness to disturbances

Question 15

In control systems, which of the following sensors is NOT typically used to measure fluid pressure?

Accepted Answer

Strain gauge

Answer

Pressure transducer

Answer

Piezoelectric sensor

Answer

Capacitive sensor

Question 16

In a PID control system, what is the main purpose of the derivative term?

Accepted Answer

Enhances the system's response to sudden changes in the input

Answer

Eliminates overshoot in the system's response

Answer

Ensures the system's stability under disturbances

Answer

Reduces steady-state error to zero

Question 17

In control systems, which sensor is specifically designed for precise measurement of fluid pressure?

Accepted Answer

Pressure transducer

Answer

Thermistor

Answer

Accelerometer

Answer

Strain gauge

Question 18

A system is described by the transfer function G(s) = (s+2)/(s^2 + 4s + 3). If the system is subjected to a unit step input, determine the steady-state value of the system's output.

Accepted Answer

2/3

Answer

0

Answer

1

Question 19

In model predictive control (MPC), which statement holds true?

Accepted Answer

MPC requires an accurate system model for future behavior prediction.

Answer

MPC is only suitable for linear systems.

Answer

MPC always ensures optimal control performance.

Answer

MPC is mainly employed for feedforward control.

Question 20

The transfer function of a system characterizes the relationship between the system's:

Accepted Answer

Input and output

Answer

Input and error

Answer

Output and disturbance

Answer

Poles and zeros

Question 21

The Nyquist criterion for stability is based on the analysis of the:

Accepted Answer

Open-loop transfer function

Answer

Closed-loop transfer function

Answer

System's poles and zeros

Answer

System's input and output signals

Question 22

The gain margin of a control system provides a measure of its robustness to:

Accepted Answer

Gain variations in the open-loop transfer function

Answer

Phase variations in the open-loop transfer function

Answer

Time delays in the system

Answer

Sensor noise

Question 23

Which of the following is **not** a common type of system model employed in control engineering?

Accepted Answer

Neural network model

Answer

Transfer function model

Answer

State space model

Answer

Block diagram model

Question 24

The frequency response plot of a system exemplifies:

Accepted Answer

Variation in system output in relation to input frequency

Answer

Variation in system stability in relation to input frequency

Answer

Variation in system damping ratio in relation to input frequency

Answer

Variation in system phase margin in relation to input frequency

Question 25

The stability of a control system is principally determined by:

Accepted Answer

The location of its poles in the complex plane

Answer

The magnitude of its frequency response

Answer

The settling time of its step response

Answer

The overshoot of its step response

Question 26

The Bode plot visually represents a system's:

Accepted Answer

Frequency response

Answer

Transfer function

Answer

Root locus

Answer

Nyquist diagram

Question 27

A key benefit of utilizing a state space model in control system design is:

Accepted Answer

Providing a direct approach for state feedback control

Answer

Enabling the modelling of more intricate systems

Answer

Simplified analysis compared to transfer function models

Answer

Enhanced accuracy for systems with time delays

Question 28

The Nyquist stability criterion serves to assess:

Accepted Answer

The stability of a closed-loop control system

Answer

The frequency response of an open-loop system

Answer

The root locus of a system

Answer

The Bode plot of a system

Question 29

A common method employed for designing a PID controller is:

Accepted Answer

Ziegler-Nichols method

Answer

Bode method

Answer

Root locus method

Answer

State space method

Question 30

The primary objective of a lead compensator is to:

Accepted Answer

Increase the phase margin of a system

Answer

Decrease the gain margin of a system

Answer

Increase the settling time of a system

Answer

Decrease the overshoot of a system

Question 31

A defining feature of a control system incorporating integral action is:

Accepted Answer

Zero steady-state error for step input

Answer

Infinite gain margin

Answer

Positive phase margin

Answer

No overshoot in step response

Question 32

In an adaptive control system, how does parameter estimation contribute to its ability to adapt to unknown plant dynamics and enhance tracking performance?

Accepted Answer

It enables continuous adjustment of controller parameters to match changing plant dynamics.

Answer

It eliminates the need for manual parameter tuning.

Answer

It guarantees optimal performance under all operating conditions.

Answer

It makes a system model unnecessary.

Question 33

Which of the following is not a classification of control systems?

Accepted Answer

Discrete-event

Answer

Continuous-time

Answer

Sampled-data

Answer

Adaptive

Question 34

Which of the following is a characteristic of a stable control system?

Accepted Answer

Bounded output

Answer

Negative feedback

Answer

Zero error in steady-state

Answer

Positive gain

Question 35

A PI controller has a transfer function of Kp + Ki/s. What is the primary advantage of using a PI controller over a PD controller?

Accepted Answer

Eliminates steady-state error

Answer

Improves system stability

Answer

Increases system bandwidth

Answer

Reduces sensitivity to noise

Question 36

What is a transfer function?

Accepted Answer

A mathematical representation of a system's response to an input signal

Answer

A graphical representation of a system's frequency response

Answer

A differential equation that describes the system's dynamics

Answer

A state-space representation of the system

Question 37

What is the order of a system with a transfer function having two poles?

Accepted Answer

2

Answer

1

Answer

3

Answer

4

Question 38

What is the primary purpose of a Bode plot?

Accepted Answer

To determine the frequency response of a system

Answer

To design a controller for a system

Answer

To compute the system's time response

Answer

To simulate the system's behaviour

Question 39

What is the Nyquist stability criterion used for?

Accepted Answer

Graphically determining the stability of a system

Answer

Mathematically calculating the system's poles

Answer

Simulating the system's response

Answer

Optimizing the design of controllers

Question 40

What is the fundamental difference between a closed-loop and an open-loop control system?

Accepted Answer

Closed-loop systems use feedback, while open-loop systems do not

Answer

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

Answer

Closed-loop systems are always linear, while open-loop systems can be nonlinear

Answer

Open-loop systems are used for controlling fast processes, while closed-loop systems are used for controlling slow processes

Question 41

In a control system with a digital controller, how does quantization noise impact its performance? Explain two techniques used to mitigate its effects.

Accepted Answer

Dithering and noise shaping are effective techniques for reducing quantization noise.

Answer

Quantization noise has a negligible impact on control system performance.

Answer

Increasing the sampling rate of the digital controller can eliminate quantization noise.

Question 42

In the analysis of control systems, which technique is most suitable for determining the stability of a system characterized by multiple poles?

Accepted Answer

Routh-Hurwitz criterion

Answer

Nyquist criterion

Answer

Bode plot

Answer

Root locus

Question 43

Which of the following is NOT an advantage of using transfer functions in control systems analysis?

Accepted Answer

Providing a physical model of the system

Answer

Simplifying complex systems for easier analysis

Answer

Predicting system response to different inputs

Answer

Designing controllers to improve system performance

Question 44

Consider a system with the transfer function G(s) = s/(s^2 + 2s + 1). What is the order of this system?

Accepted Answer

2

Answer

0

Answer

1

Answer

3

Question 45

The frequency at which the magnitude of a system's frequency response is maximum is known as:

Accepted Answer

Resonance frequency

Answer

Natural frequency

Answer

Cutoff frequency

Answer

Pole frequency

Question 46

When designing path planning control systems for autonomous vehicles, which three key considerations are paramount?

Accepted Answer

Sensor fusion, obstacle avoidance, and trajectory optimization

Answer

Sensor calibration, network connectivity, and data security

Answer

User interface design, passenger comfort, and vehicle aesthetics

Question 47

Discuss the advantages and limitations of using Model Predictive Control (MPC) in complex control systems, exploring its applications across various industries.

Accepted Answer

MPC enhances performance and robustness, but its computational complexity and reliance on model accuracy can be challenging.

Answer

MPC is not universally applicable to all industries and may not be the best solution for every complex control problem.

Answer

MPC is not universally applicable to all industries and may not be the best solution for every complex control problem.

Answer

MPC is not universally applicable to all industries and may not be the best solution for every complex control problem.

Question 48

What is a key benefit of using integral control in a feedback control system?

Accepted Answer

Elimination of steady-state errors

Answer

Improved transient response

Answer

Reduced system stability

Answer

Increased system bandwidth

Question 49

How does negative feedback contribute to the stability and error reduction in control systems?

Accepted Answer

Negative feedback compares the system output to the reference input, calculates the error, and feeds it back to adjust the input to reduce the error.

Answer

Negative feedback increases system gain, making it more responsive to input changes.

Answer

Negative feedback destabilizes the system and amplifies errors.

Answer

Negative feedback has no impact on either system stability or error reduction.

Question 50

Which of the following is NOT a characteristic of a linear control system?

Accepted Answer

Nonlinearity

Answer

Scalability

Answer

Superposition

Answer

Time-invariance

Question 51

A control system is stable if the real parts of all its poles lie in the:

Accepted Answer

Left half of the complex plane

Answer

Imaginary axis

Answer

Origin

Answer

Right half of the complex plane

Question 52

The state-space representation of a system:

Accepted Answer

Describes the system's internal dynamics and input-output relationships

Answer

Only models the system's inputs and outputs

Answer

Cannot be used to determine the system's frequency response

Answer

Only models the system's internal dynamics

Question 53

The feedback control loop typically consists of:

Accepted Answer

Sensor, controller, actuator, plant

Answer

Controller, sensor, actuator, plant

Answer

Actuator, plant, controller, sensor

Answer

Plant, controller, sensor, actuator

Question 54

The primary purpose of a control system is to:

Accepted Answer

Maintain a desired output despite disturbances

Answer

Stabilize the system without external influences

Answer

Reduce the system's input

Answer

Increase the system's output

Question 55

A system's transfer function relates the system's:

Accepted Answer

Output to the input in the frequency domain

Answer

Stability to the location of its poles

Answer

Time domain response to its inputs

Question 56

A common type of feedback controller is the:

Accepted Answer

Proportional-integral-derivative (PID) controller

Answer

Lag compensator

Answer

On-off controller

Question 57

The root locus plot graphically depicts:

Accepted Answer

The closed-loop poles as a function of a system parameter

Answer

The system's frequency response

Answer

The open-loop poles and zeros

Question 58

A transfer function is a mathematical representation of:

Accepted Answer

The relationship between input and output of a system in the frequency domain

Answer

The time-domain response of a system to a step input

Answer

The transient response of a system to a disturbance

Answer

The stability of a system

Question 59

The frequency response of a system is a plot of:

Accepted Answer

Output magnitude and phase as a function of frequency

Answer

Input and output signals in the time domain

Answer

Gain and phase margin

Answer

System poles and zeros

Question 60

A proportional-integral-derivative (PID) controller is used to:

Accepted Answer

Reduce steady-state error and improve transient response

Answer

Reduce noise sensitivity

Answer

Increase system stability

Answer

Compensate for nonlinearities

Question 61

The transfer function of a first-order system with a gain of K and a time constant of a is:

Accepted Answer

G(s) = K / (s + a)

Answer

G(s) = s / (s + a)

Answer

G(s) = K / (s^2 + a)

Question 62

Which of the following is NOT a classification of control systems based on the presence or absence of feedback?

Accepted Answer

Feedforward system

Answer

Closed-loop system

Answer

Open-loop system

Question 63

The Bode plot is a graphical representation used to analyze a control system's:

Accepted Answer

Frequency response

Answer

Time response

Answer

Stability

Question 64

Which of the following performance metrics quantifies a system's ability to minimize the effect of external disturbances?

Accepted Answer

Disturbance rejection ratio

Answer

Gain margin

Answer

Phase margin