# Control Systems Multiple-Choice Questions (MCQs)

A Control System is a system in which the output is controlled by varying the input.

**Control Systems MCQs**: This section contains multiple-choice questions and answers on the various topics of Control Systems. Practice these MCQs to test and enhance your skills on Control Systems.

## List of Control Systems MCQs

**1. The 1st control system device was invented in the year -**

- 1766
- 1767
- 1768
- 1769

**Answer:** B) 1767

**Explanation:**

The 1st control system device was invented in the year 1767.

**2. What describes the behavior of the control systems?**

- Equations
- Rational Equations
- Differential Equations
- Integration Equations

**Answer:** C) Differential Equations

**Explanation:**

Differential Equations describe the behavior of the control systems.

**3. How many types of control systems are there?**

- 2
- 3
- 4
- 5

**Answer:** A) 2

**Explanation:**

There are 2 types of control systems.

**4. Which of the following is/are the type(s) of control systems?**

- Open-loop control system
- Control loop control system
- Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

The following are the types of control systems -

- Open-loop control system
- Control loop control system

**5. ____ loop is a control system in which the desired output signal is not affected by the control action**

- Open
- Closed
- Both A and B
- None of the above

**Answer:** A) Open

**Explanation:**

Open loop is a control system in which the desired output signal is not affected by the control action.

**6. What is an open loop control system also known as?**

- Non-feedback control system
- Control system without feedback
- Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

The open-loop control system is also known as -

- Non-feedback control system
- Control system without feedback

**7. Which of the following is/are the example(s) of the open loop control system?**

- Automating washing machine
- Immersion rod
- Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

The following are the examples of the open loop control system -

- Automating washing machine
- Immersion rod

**8. What is/are the advantage(s) of an open-loop control system?**

- Simple
- Economical
- Low maintenance
- All of the above

**Answer:** D) All of the above

**Explanation:**

The advantages of an open loop control system are -

- Simple
- Economical
- Low maintenance

**9. What is/are the disadvantage(s) of an open loop control system?**

- Inaccurate
- Not reliable
- Slow
- All of the above

**Answer:** D) All of the above

**Explanation:**

The disadvantages of an open loop control system are -

- Inaccurate
- Not reliable
- Slow

**10. Control actions in a closed loop are determined by ____.**

- Inputs
- Outputs
- Both A and B
- None of the above

**Answer:** B) Outputs

**Explanation:**

Control actions in a closed loop are determined by outputs.

**11. Using ____ loop control, an error signal is generated when the output signal varies from the reference input signal, and the error signal is fed to the controller to reduce the error.**

- Open
- Closed
- Both A and B
- None of the above

**Answer:** B) Closed

**Explanation:**

Using closed-loop control, an error signal is generated when the output signal varies from the reference input signal, and the error signal is fed to the controller to reduce the error.

**12. What is/are the advantage(s) of closed-loop control systems?**

- Reliable
- Fast
- Optimizable
- All of the above

**Answer:** D) All of the above

**Explanation:**

The advantages of closed-loop control systems are -

- Reliable
- Fast
- Optimizable

**13. What is/are the disadvantage(s) of open loop control systems?**

- Expensive
- High Maintenance
- Difficult installation
- All of the above

**Answer:** D) All of the above

**Explanation:**

The disadvantages of open loop control systems are -

- Expensive
- High Maintenance
- Difficult installation

**14. In order to accomplish a certain task, a system consists of ____ components that work together.**

- Same
- Similar
- Various
- None

**Answer:** C) Various

**Explanation:**

In order to accomplish a certain task, a system consists of various components that work together.

**15. A ____ system is composed of physical objects working together to achieve a specific goal, such as a classroom.**

- Physical
- Virtual
- Real
- Mental

**Answer:** A) Physical

**Explanation:**

A physical system is composed of physical objects working together to achieve a specific goal, such as a classroom.

**16. ____ are the three controls on an air conditioner.**

- Temperature control
- Humidistat
- Airstat
- All of the above

**Answer:** D) All of the above

**Explanation:**

Temperature control, humidistat, and airstat are the three controls on an air conditioner.

**17. An area of the process that is being ____ is called the plant.**

- Regulated
- Controlled
- Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

An area of the process that is being regulated or controlled is called the plant.

**18. An ____ relationship without feedback is known as a transfer function in a control system.**

- Input-input
- Output-output
- Input-output
- None of the above

**Answer:** C) Input-output

**Explanation:**

An input-output relationship without feedback is known as a transfer function in a control system.

**19. System input variables are generally referred to as ____, and outputs as controller outputs.**

- Reference Inputs
- Reference Outputs
- Controller Inputs
- None of the above

**Answer:** A) Reference Inputs

**Explanation:**

System input variables are generally referred to as reference inputs, and controller outputs as controller outputs.

**20. A controller minimizes the difference between a system's ____ by reducing the error.**

- Actual Value
- Desired Value
- Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

A controller minimizes the difference between a system's actual value and its desired value by reducing the error.

**21. Which of the following is/are TRUE about Inputs?**

- A control system generates the desired output by receiving an
- input signal from an external energy source.

Any response in a system can be produced by this desired action. - Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

The following are TRUE about Inputs -

- A control system generates the desired output by receiving an
- input signal from an external energy source.

Any response in a system can be produced by this desired action.

**22. ____ are common input types used in control systems.**

- SISO
- MIMO
- Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

SISO and MIMO are common input types used in control systems.

**23. What is the full form of SISO?**

- Single Input Single Output
- Simple Input Simple Output
- Simple Input Single Output
- Single Input Simple Output

**Answer:** A) Single Input Single Output

**Explanation:**

The full form of SISO is Single Input Single Output.

**24. What is the full form of MIMO?**

- Multiple Input Multiple Option
- Multiple Input Multiple Output
- Multiple Instant Multiple Option
- Multiple Instant Multiple Output

**Answer:** B) Multiple Input Multiple Output

**Explanation:**

The full form of MIMO is Multiple Input Multiple Output.

**25. Control systems refer to reference inputs as ____.**

- Set-points
- Desired values
- Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

Control systems refer to reference inputs as set points or desired values.

**26. Signals that cause disturbances adversely affect the output value of control systems are called ____.**

- Inputs
- Outputs
- Disturbances
- None of the above

**Answer:** C) Disturbances

**Explanation:**

Signals that cause disturbances adversely affect the output value of control systems are called disturbances.

**27. An ____ control system, such as an autopilot, operates without human intervention.**

- Automatic
- Manual
- Linear
- Time-variant

**Answer:** A) Automatic

**Explanation:**

An automatic control system, such as an autopilot, operates without human intervention.

**28. Described as a ____ control system, a manual control system involves human intervention.**

- Automatic
- Manual
- Linear
- Time-variant

**Answer:** B) Manual

**Explanation:**

Described as a manual control system, a manual control system involves human intervention.

**29. Known as a ____ system, it describes the relationship between inputs and outputs using a linear differential equation.**

- Manual
- Linear
- Time-variant
- Time-invariant

**Answer:** B) Linear

**Explanation:**

Known as a linear system, it describes the relationship between inputs and outputs using a linear differential equation.

**30. ____ control systems are also known as the superposition principle.**

- Automatic
- Linear
- Time-variant
- Time-invariant

**Answer:** B) Linear

**Explanation:**

Linear control systems are also known as the superposition principle.

**31. ____ systems are defined by differential equations with variable coefficients that describe the input-output relationship.**

- Time-variant
- Time-invariant
- Linear
- Automatic

**Answer:** A) Time-variant

**Explanation:**

Time-variant systems are defined by differential equations with variable coefficients that describe the input-output relationship.

**32. ____ systems are those whose input and output relationships are described by differential equations with constant coefficients.**

- Time-variant
- Time-invariant
- Linear
- Manual

**Answer:** B) Time-invariant

**Explanation:**

Time-invariant systems are those whose input and output relationships are described by differential equations with constant coefficients.

**33. Various components make up a system, including ____, thermal, and chemical components.**

- Electrical
- Hydraulic
- Mechanical
- All of the above

**Answer:** D) All of the above

**Explanation:**

Various components make up a system, including electrical, hydraulic, mechanical, thermal, and chemical components.

**34. What is/are the basic concept(s) of the control system?**

- Minimize the error
- Minimize the time-response
- Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

The basic concepts of the control system are -

- Minimize the error
- Minimize the time-response

**35. What is/are the classification(s) of the control system?**

- Linear or non-linear systems can be designed based on the methods used for analysis and design.
- There are many different types of control systems, including time-varying, time-invariant, continuous, discrete, modulated, or unmodulated systems.
- In addition to electromechanical, biological, hydraulic, thermal, and pneumatic control systems, a number of other types of control systems can also be used.
- All of the above

**Answer:** D) All of the above

**Explanation:**

The classifications of the control system are -

- Linear or non-linear systems can be designed based on the methods used for analysis and design.
- There are many different types of control systems, including time-varying, time-invariant, continuous, discrete, modulated, or unmodulated systems.
- In addition to electromechanical, biological, hydraulic, thermal, and pneumatic control systems, a number of other types of control systems can also be used.

**36. ____ systems possess both homogeneity and superposition properties in order to be considered linear.**

- Linear
- Non-linear
- Both A and B
- None of the above

**Answer:** A) Linear

**Explanation:**

Linear systems possess both homogeneity and superposition properties in order to be considered linear.

**37. A ____ system is one whose output is not directly proportional to its input or one that does not satisfy the superposition principle or homogeneity property.**

- Linear
- Non-linear
- Both A and B
- None of the above

**Answer:** B) Non-linear

**Explanation:**

A non-linear system is one whose output is not directly proportional to its input or one that does not satisfy the superposition principle or homogeneity property.

**38. ____ control systems have parameters that vary with time, while time-invariant control systems do not have parameters that change with time.**

- Time-varying
- Time-invariant
- Both A and B
- None of the above

**Answer:** A) Time-varying

**Explanation:**

Time-varying control systems have parameters that vary with time, while time-invariant control systems do not have parameters that change with time.

**39. A ____ data control system is a system that is controlled by a signal as pulses, rather than continuously varying with time.**

- Continuous
- Discrete
- Both A and B
- None of the above

**Answer:** B) Discrete

**Explanation:**

A discrete data control system is a system that is controlled by a signal as pulses, rather than continuously varying with time.

**40. Which of the following is/are the type(s) of a discrete data control system?**

- Sampled
- Digital
- Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

The following types of discrete data control systems are there -

- Sampled
- Digital

**41. The system is known as a ____ data control system if the signal is pulsed data.**

- Sampled
- Digital
- Both A and B
- None of the above

**Answer:** A) Sampled

**Explanation:**

The system is known as a sampled data control system if the signal is pulsed data.

**42. In a digital control system, the signal is represented as ____ code.**

- Analytical
- Sampled
- Digital
- Digi

**Answer:** C) Digital

**Explanation:**

In a digital control system, the signal is represented as digital code.

**43. The output of a ____ system is one that does not change over time with the input.**

- Static
- Dynamic
- Both A and B
- None of the above

**Answer:** A) Static

**Explanation:**

The output of a static system is one that does not change over time with the input.

**44. A system that produces a variable output even with constant input is referred to as a ____ system.**

- Static
- Dynamic
- Both A and B
- None of the above

**Answer:** B) Dynamic

**Explanation:**

A system that produces a variable output even with constant input is referred to as a dynamic system.

**45. Control systems must be ____.**

- Stable
- Accurate
- Responsive
- All of the above

**Answer:** D) All of the above

**Explanation:**

Control systems must be stable, accurate, and responsive.

**46. The characteristic equation is ____ if all of its roots lie on the left half of the s-plane**

- Stable
- Unstable
- Dominant
- None

**Answer:** A) Stable

**Explanation:**

The characteristic equation is stable if all of its roots lie on the left half of the s-plane.

**47. An ____ system occurs if one or more roots are on the right half of the s-plane.**

- Stable
- Unstable
- Dominant
- None

**Answer:** B) Unstable

**Explanation:**

An unstable system occurs if one or more roots are on the right half of the s-plane.

**48. A system that has ____ poles is considered unstable.**

- Repetitive
- Non-repetitive
- Both A and B
- None of the above

**Answer:** A) Repetitive

**Explanation:**

A system that has repetitive poles is considered unstable.

**49. In the left half of the s-plane, ____ poles are those that are close to the origin.**

- Submissive
- Dominant
- Both A and B
- None of the above

**Answer:** B) Dominant

**Explanation:**

In the left half of the s-plane, the dominant poles are those that are close to the origin.

**50. A stable system can be categorized as -**

- Absolute
- Conditional
- Marginal
- All of the above

**Answer:** D) All of the above

**Explanation:**

Stable system can be categorized as -

- Absolute
- Conditional
- Marginal

**51. ____ stable systems are those that are stable across all ranges.**

- Absolute
- Conditional
- Marginal
- None

**Answer:** A) Absolute

**Explanation:**

Absolute stable systems are those that are stable across all ranges.

**52. The system is said to be ____ stable if it is stable within a certain range of values.**

- Absolutely
- Conditionally
- Marginally
- None

**Answer:** B) Conditionally

**Explanation:**

The system is said to be conditionally stable if it is stable within a certain range of values.

**53. When a system oscillates at a constant frequency and with constant amplitude, it is said to be ____ stable.**

- Absolutely
- Conditionally
- Marginally
- None

**Answer:** C) Marginally

**Explanation:**

When a system oscillates at a constant frequency and with constant amplitude, it is said to be marginally stable.

**54. ____ refers to the degree to which the measured value is close to the true value.**

- Stability
- Accuracy
- Response
- All of the above

**Answer:** B) Accuracy

**Explanation:**

Accuracy refers to the degree to which the measured value is close to the true value.

**55. Known as the system's ____, an instrument changes its output signal in response to a change in its output signal.**

- Stability
- Response
- Accuracy
- None

**Answer:** B) Response

**Explanation:**

Known as the system's response, an instrument changes its output signal in response to a change in its output signal.

**56. Which of the following is/are the type(s) of the physical system?**

- Mechanical
- Electrical
- Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

The following are the types of a physical systems -

- Mechanical
- Electrical

**57. Which of the following is/are the type(s) of the mechanical system?**

- Translational
- Linear
- Rotational
- All of the above

**Answer:** D) All of the above

**Explanation:**

The following types of mechanical systems are there -

- Translational
- Linear
- Rotational

**58. An angular motion is referred to as a ____ motion.**

- Translational
- Linear
- Both A and B
- None of the above

**Answer:** A) Translational

**Explanation:**

An angular motion is referred to as a translational motion.

**59. How many types of forces are there in the translational system?**

- 2
- 3
- 4
- 5

**Answer:** B) 3

**Explanation:**

There are 3 types of forces in the translational system.

**60. Which of the following is/are the type(s) of the translational system?**

- Inertia Force
- Damping Force
- Spring Force
- All of the above

**Answer:** D) All of the above

**Explanation:**

The following are the types of the translational system -

- Inertia Force
- Damping Force
- Spring Force

**61. Known as ____ motion, this type of motion involves a body rotating around a fixed axis.**

- Linear
- Rotational
- Circular
- Transitional

**Answer:** B) Rotational

**Explanation:**

Known as rotational motion, this type of motion involves a body rotating around a fixed axis.

**62. The torques that resist rotation are divided into ____ types**

- Two
- Three
- Four
- Five

**Answer:** B) Three

**Explanation:**

The torques that resist rotation are divided into three types.

**63. An element's ____ refers to its capacity to store the energy of rotation**

- Inertia
- Damping
- Spring
- None

**Answer:** A) Inertia

**Explanation:**

An element's inertia refers to its capacity to store the energy of rotation.

**64. ____ are the two factors that determine Damping Torque.**

- Angular Velocity
- Damping Coefficient
- Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

Angular velocity and damping coefficient are the two factors that determine Damping Torque.

**65. ____ combine to form spring torque.**

- Torsion
- Angular Displacement
- Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

Torsion and angular displacement combine to form spring torque.

**66. Whenever all the initial conditions are zero, a system's ____ function is the ratio of its output to its input.**

- Transitional
- Transfer
- Transport
- Transit

**Answer:** B) Transfer

**Explanation:**

Whenever all the initial conditions are zero, a system's transfer function is the ratio of its output to its input.

**67. For the ____ of the transfer function, zero is the frequency at which the transfer function becomes valid.**

- Zeros
- Poles
- Both A and B
- None of the above

**Answer:** B) Poles

**Explanation:**

For the poles of the transfer function, zero is the frequency at which the transfer function becomes valid.

**68. The ____ in a transfer function represents the frequencies at which the transfer function no longer exists.**

- Zeros
- Poles
- Both A and B
- None of the above

**Answer:** A) Zeros

**Explanation:**

The zeros in a transfer function represent the frequencies at which the transfer function no longer exists.

**69. In the case of ____, the poles or zeros are said to be multiple if they coincide.**

- Multiple Poles
- Multiple Zeros
- Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

In the case of multiple poles or multiple zeros, the poles or zeros are said to be multiple if they coincide.

**70. A ____ is one with poles and zeros that do not coincide**

- Simple Pole
- Simple Zero
- Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

A simple pole or simple zero is one with poles and zeros that do not coincide.

**71. Known as the ____, a crossed circle represents the summation of an input signal.**

- Summing Point
- Take off Point
- Both A and B
- None of the above

**Answer:** A) Summing Point

**Explanation:**

Known as the summing point, a crossed circle represents the summation of an input signal.

**72. In the case where there are multiple blocks and we want to apply the same input to all blocks, we use ____ points.**

- Summing
- Take-off
- Take-down
- Take-up

**Answer:** B) Take-off

**Explanation:**

In the case where there are multiple blocks and we want to apply the same input to all blocks, we use take-off points.

**73. ____-loop control refers to a system where a feedback path exists.**

- Open
- Closed
- Both A and B
- None of the above

**Answer:** B) Closed

**Explanation:**

Closed-loop control refers to a system where a feedback path exists.

**74. It is the product of two or more blocks that are formed when they are connected in ____.**

- Series
- Parallel
- Both A and B
- None of the above

**Answer:** A) Series

**Explanation:**

It is the product of two or more blocks that are formed when they are connected in series.

**75. A ____ connection of two or more blocks results in a block that contains the sum of its two or more parts.**

- Series
- Parallel
- Dot
- Side

**Answer:** B) Parallel

**Explanation:**

A parallel connection of two or more blocks results in a block that contains the sum of its two or more parts.

**76. What is the full form of SFG?**

- Sign Flow Graph
- Signal Flow Graph
- Signal Fly Graph
- Simple Flow Graph

**Answer:** B) Signal Flow Graph

**Explanation:**

The full form of SFG is Signal Flow Graph.

**77. Which of the following is/are the characteristic(s) of SFG?**

- There are nodes in the network which represent system variables, and direct branches connect them.
- Diagrams representing equations are called SFGs.
- The linear system is the only one that can be applied to it.
- All of the above

**Answer:** D) All of the above

**Explanation:**

The following are the characteristics of SFG -

- There are nodes in the network which represent system variables, and direct branches connect them.
- Diagrams representing equations are called SFGs.
- The linear system is the only one that can be applied to it.

**78. In the ____, all signals are represented as a system variable.**

- Node
- Branch
- Loop
- Forward Path

**Answer:** A) Node

**Explanation:**

In the node, all signals are represented as a system variable.

**79. The arrow of the ____ indicates the direction in which the branch goes from one node to another.**

- Node
- Branch
- Input Node
- Source

**Answer:** B) Branch

**Explanation:**

The arrow of the branch indicates the direction in which the branch goes from one node to another.

**80. It is the node that has only outgoing branches that are considered an ____.**

- Input Node
- Source
- Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

It is the node that has only outgoing branches that are considered an input node or source.

**81. Nodes with only incoming branches are ____.**

- Output nodes
- Sinks
- Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

Nodes with only incoming branches are output nodes or sinks.

**82. From an input node to an output node, ____ paths follow the direction of branch arrows.**

- Backward
- Forward
- Side-by-side
- None

**Answer:** B) Forward

**Explanation:**

From an input node to an output node, forward paths follow the direction of branch arrows.

**83. ____ start at the same node and ends there.**

- Loop
- Non-touching loop
- Forward path gain
- Loop gain

**Answer:** A) Loop

**Explanation:**

Loops start at the same node and end there.

**84. Loops that do not have a common node are said to be ____.**

- Non-touching
- Touching
- Breaking
- Non-breaking

**Answer:** A) Non-touching

**Explanation:**

Loops that do not have a common node are said to be non-touching.

**85. ____ path gain is the sum of all branch gains along the forward path.**

- Forward
- Backward
- Side-by-side
- None

**Answer:** A) Forward

**Explanation:**

Forward path gain is the sum of all branch gains along the forward path.

**86. Branch ____ travels through a loop and is multiplied by loop gain.**

- Gain
- Loss
- Both A and B
- None of the above

**Answer:** A) Gain

**Explanation:**

Branch gain travels through a loop and is multiplied by loop gain.

**87. Mason's ____ Formula describes the relationship between input variables and output variables in a signal flow graph.**

- Gain
- Loss
- Average
- Functional

**Answer:** A) Gain

**Explanation:**

Mason's Gain Formula describes the relationship between input variables and output variables in a signal flow graph.

**88. An evaluation of the system's performance in a given time period is the primary purpose of ____ analysis.**

- Time No-response
- Time response
- Time Waiting
- Time No-waiting

**Answer:** B) Time response

**Explanation:**

An evaluation of the system's performance in a given time period is the primary purpose of time response analysis.

**89. Time response consists of two parts -**

- Transient
- Steady State
- Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

Time response consists of two parts: transient and steady state.

**90. Responses that are transient can also be referred to as ____ responses.**

- Steady
- Temporary
- Both A and B
- None of the above

**Answer:** B) Temporary

**Explanation:**

Responses that are transient can also be referred to as temporary responses.

**91. Which of the following is/are the standard signal(s)?**

- Step Input
- Ramp Input
- Impulse Input
- All of the above

**Answer:** D) All of the above

**Explanation:**

The following are the standard signals -

- Step Input
- Ramp Input
- Impulse Input

**92. ____ is the period of time required for states to change.**

- Transient Time
- Transient Response
- Steady Time
- Steady Response

**Answer:** A) Transient Time

**Explanation:**

Transient time is the period of time required for states to change.

**93. In the transient time period, ____ are at their highest levels.**

- Currents
- Voltages
- Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

In the transient time period, currents and voltages are at their highest levels.

**94. A control system's time response can be divided into the following category/ies -**

- Transient Response Analysis
- Steady State Analysis
- Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

A control system's time response can be divided into the following -

- Transient Response Analysis
- Steady State Analysis

**95. When a system is subjected to an input, it exhibits a ____ state response.**

- Transient
- Steady
- Both A and B
- None of the above

**Answer:** A) Transient

**Explanation:**

When a system is subjected to an input, it exhibits a transient state response.

**96. A ____ state response aims to estimate the magnitude of overall input-output errors over time.**

- Steady
- Transient
- Both A and B
- None of the above

**Answer:** A) Steady

**Explanation:**

A steady-state response aims to estimate the magnitude of overall input-output errors over time.

**97. What is/are the characteristic(s) of Time-domain analysis?**

- There are several types of transfer functions that represent a control system.
- Depending on the type of system, a steady-state analysis is performed.
- G(S).H(S) is used to determine the type of system.
- All of the above

**Answer:** D) All of the above

**Explanation:**

The characteristics of Time-domain analysis are -

- There are several types of transfer functions that represent a control system.
- Depending on the type of system, a steady-state analysis is performed.
- G(S).H(S) is used to determine the type of system.

**98. What is/are the common transient response characteristic(s)?**

- Delay Time
- Rise Time
- Peak Time
- All of the above

**Answer:** D) All of the above

**Explanation:**

The common transient response characteristics are -

- Delay Time
- Rise Time
- Peak Time

**99. Defining the ____ as the amount of time it takes to reach 50% of the final value in the first attempt.**

- Delay Time
- Rise Time
- Peak Time
- Settling Time

**Answer:** A) Delay Time

**Explanation:**

Defining the delay time as the amount of time it takes to reach 50% of the final value in the first attempt.

**100. Known as ____, it is the time required for an overdamped system to adjust from 10% to 90% of its final value, and for an underdamped system to adjust from 0 to 100%.**

- Delay Time
- Rise Time
- Peak Time
- Settling Time

**Answer:** B) Rise Time

**Explanation:**

Known as rise time, it is the time required for an overdamped system to adjust from 10% to 90% of its final value, and for an underdamped system to adjust from 0 to 100%.

**101. During the ____, the response reaches the 1st peak overshoot or peak of the response.**

- Delay Time
- Rise Time
- Peak Time
- Settling Time

**Answer:** C) Peak Time

**Explanation:**

During the peak time, the response reaches the 1st peak overshoot or peak of the response.

**102. There is a difference between the peak output at the beginning and the steady output at the end of the cycle called the ____.**

- Settling Time
- Maximum Overshoot
- Delay Time
- Rise Time

**Answer:** B) Maximum Overshoot

**Explanation:**

There is a difference between the peak output at the beginning and the steady output at the end of the cycle, called the maximum overshoot.

**103. A response's ____ is the amount of time it takes to reach and stay within the specified range (2% to 5%).**

- Setting Time
- Settling Time
- Sitting Time
- None

**Answer:** B) Settling Time

**Explanation:**

A response's settling time is the amount of time it takes to reach and stay within the specified range (2% to 5%).

**104. A ____ describes how an actual output differs from the desired output as time 't' approaches infinity.**

- Steady State Error
- Steady Transient Error
- Both A and B
- None of the above

**Answer:** A) Steady State Error

**Explanation:**

A steady-state error describes how an actual output differs from the desired output as time 't' approaches infinity.

**105. Control systems must be ____ in order to function properly.**

- Stable
- Unstable
- Both A and B
- None of the above

**Answer:** A) Stable

**Explanation:**

Control systems must be stable in order to function properly.

**106. What is the full form of LTI?**

- Linear Time-Invariant
- Linear Time-Iteration
- Linear Time-Irrational
- Linear Transition-Invariant

**Answer:** A) Linear Time-Invariant

**Explanation:**

The full form of LTI is Linear Time-Invariant.

**107. What is the full form of BIBO?**

- Bounded Input Bounded Output
- Boundless Input Bounded Output
- Bounded Input Boundless Output
- Boundless Input Boundless Output

**Answer:** A) Bounded Input Bounded Output

**Explanation:**

The full form of BIBO is Bounded Input Bounded Output.

**108. What comes under the basic concept(s) of the Routh Hurwitz Criteria?**

- As a result of the Routh criteria, one does not have a precise idea of the root locations of the characteristic equation whose roots are located on the right half of the s-plane.
- Real or complex roots cannot be determined by this method.
- A linear system is the only one that works with it.
- All of the above

**Answer:** D) All of the above

**Explanation:**

The basic concepts of Routh Hurwitz Criteria are -

- As a result of the Routh criteria, one does not have a precise idea of the root locations of the characteristic equation whose roots are located on the right half of the s-plane.
- Real or complex roots cannot be determined by this method.
- A linear system is the only one that works with it.

**109. What is/are the advantage(s) of the Routh Hurwitz Criterion?**

- Solving the equation is not necessary to find the system's stability.
- A system's relative stability can easily be determined.
- The range of K for stability can be determined using this method.
- All of the above

**Answer:** D) All of the above

**Explanation:**

The advantages of the Routh Hurwitz Criterion are -

- Solving the equation is not necessary to find the system's stability.
- A system's relative stability can easily be determined.
- The range of K for stability can be determined using this method.

**110. What is/are the limitation(s) of the Routh Hurwitz Criterion?**

- Only linear systems are subject to this criterion.
- On the right and left halves of the S plane, it does not provide the exact location of the poles.
- This equation can only be used for real coefficients when dealing with the characteristic equation.
- All of the above

**Answer:** D) All of the above

**Explanation:**

The limitations of the Routh Hurwitz Criterion are -

- Only linear systems are subject to this criterion.
- On the right and left halves of the S plane, it does not provide the exact location of the poles.
- This equation can only be used for real coefficients when dealing with the characteristic equation.

**111. The Root Locus system was introduced in -**

- 1947
- 1948
- 1949
- 1950

**Answer:** B) 1948

**Explanation:**

The Root Locus system was introduced in 1948.

**112. When a specified parameter is varied from 0 to ____, the root locus can be used to locate the movement of poles in the s-plane.**

- 1
- 2
- 5
- Infinity

**Answer:** D) Infinity

**Explanation:**

When a specified parameter is varied from 0 to infinity, the root locus can be used to locate the movement of poles in the s-plane.

**113. Which of the following is/are determined using the root locus?**

- Damping Ratio
- Natural Frequency
- Lag and lead compensators
- All of the above

**Answer:** D) All of the above

**Explanation:**

The following are determined using the root locus -

- Damping Ratio
- Natural Frequency
- Lag and lead compensators

**114. What is the full form of PID?**

- Proportional Initial Derivative
- Proportional Integral Derivative
- Proportional Initial Dimension
- Proportional Integral Dimension

**Answer:** B) Proportional Integral Derivative

**Explanation:**

The full form of PID is Proportional Integral Derivative.

**115. What is/are the advantage(s) of Root Locus?**

- A root locus plot can be used to evaluate the system's absolute stability.
- Any point on the root locus can be found using magnitude and angle conditions.
- Improves the accuracy of system design.
- All of the above

**Answer:** D) All of the above

**Explanation:**

The advantages of Root Locus are -

- A root locus plot can be used to evaluate the system's absolute stability.
- Any point on the root locus can be found using magnitude and angle conditions.
- Improves the accuracy of system design.

**116. We can determine the ____, and settling time of the system using root locus plots.**

- Gain Margin
- Relative Stability
- Phase Margin
- All of the above

**Answer:** D) All of the above

**Explanation:**

We can determine the gain margin, relative stability, phase margin, and settling time of the system using root locus plots.

**117. Which of the following is/are the example(s) of Root Locus?**

- Create a plot containing poles and zeros.
- Draw a separate sketch of the asymptotic angle.
- Calculation of angle of arrival and departure.
- All of the above

**Answer:** D) All of the above

**Explanation:**

The following are the examples of Root Locus -

- Create a plot containing poles and zeros.
- Draw a separate sketch of the asymptotic angle.
- Calculation of angle of arrival and departure.

**118. What is/are the advantage(s) of frequency response?**

- Simple Calculation
- Simple and cheap apparatus
- Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

The advantages of frequency response are -

- Simple Calculation
- Simple and cheap apparatus

**119. In the control system designs, it is ____ to implement frequency response methods.**

- Easier
- Tougher
- Quite tougher
- Little tougher

**Answer:** A) Easier

**Explanation:**

The frequency response method is easy to implement in the designs of the control system.

**120. What is/are the disadvantage(s) of frequency response?**

- The practical Method is time-consuming
- Works better with linear system
- Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

The disadvantages of frequency response are -

- The practical Method is time-consuming
- Works better with linear system

**121. Frequency response analysis can be performed in -**

- Graphical Form
- Analytical Form
- Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

Frequency response analysis can be performed in either graphical form or analytical form.

**122. Bode Plot consists of -**

- Two Graphs
- Magnitude
- Phase
- All of the above

**Answer:** D) All of the above

**Explanation:**

Bode Plot consists of two graphs, magnitude, and phase.

**123. In polar coordinates, a ____ shows the magnitude of a given transfer function as a function of its phase angle.**

- Polar Plot
- Nyquist Plot
- Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

In polar coordinates, a polar plot or Nyquist plot shows the magnitude of a given transfer function as a function of its phase angle.

**124. From ____, the frequency is varied in the polar plot.**

- Zero to One
- Zero to Two
- One to Two
- Zero to Infinity

**Answer:** D) Zero to Infinity

**Explanation:**

From zero to infinity, the frequency is varied in the polar plot.

**125. From ____, the frequency is varied in the Nyquist plot.**

- Zero to infinity
- -Infinity to Zero
- -Infinity to Infinity
- Zero to One

**Answer:** C) -Infinity to Infinity

**Explanation:**

From -infinity to infinity, the frequency is varied in the Nyquist plot.

**126. An ____-loop system's stability can be determined by the Nyquist plot.**

- Closed
- Open
- Circular
- None

**Answer:** B) Open

**Explanation:**

An open-loop system's stability can be determined by the Nyquist plot.

**127. An analysis of the closed-loop system's ____ is performed using the Nichols Chart.**

- Frequency Response
- Stability
- Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

An analysis of the closed-loop system's frequency response and stability is performed using the Nichols Chart.

**128. The stability and strength of ____ systems are assessed with the Nichols plot.**

- Linear
- Analytical
- Singular
- Multicolour

**Answer:** A) Linear

**Explanation:**

The stability and strength of linear systems are assessed with the Nichols plot.

**129. ____-loop systems are usually plotted using the Bode Plot since it is easy to determine the stability and other parameters associated with the system.**

- Open
- Closed
- Simple
- Circular

**Answer:** A) Open

**Explanation:**

Open-loop systems are usually plotted using the Bode Plot since it is easy to determine the stability and other parameters associated with the system.

**130. What is/are the advantage(s) of the Bode Plot?**

- As well as covering high frequency, it also covers low frequency.
- In terms of the phase margin and gain margin, the Bode plot shows the relative stability of the system.
- Both closed and open loops can be drawn using it.
- All of the above

**Answer:** D) All of the above

**Explanation:**

The advantages of Bode Plot are -

- As well as covering high frequency, it also covers low frequency.
- In terms of the phase margin and gain margin, the Bode plot shows the relative stability of the system.
- Both closed and open loops can be drawn using it.

**131. For plotting on a semilog graph, Bode plots are based on ____ approximations.**

- Asymptotic
- Semi-asymptotic
- Non-asymptotic
- None

**Answer:** A) Asymptotic

**Explanation:**

For plotting on a semilog graph, Bode plots are based on asymptotic approximations.

**132. What is/are the disadvantage(s) of Bode Plot?**

- Fundamentally, the system behaves the same way all the time.
- In the case of the given transfer functions, it clearly predicts each factor's contribution.
- Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

The disadvantages of Bode Plot are -

- Fundamentally, the system behaves the same way all the time.
- In the case of the given transfer functions, it clearly predicts each factor's contribution.

**133. Orientations in polar graphs are measured ____ for positive angles and clockwise for negative angles.**

- Clockwise
- Anticlockwise
- Semiclockwise
- Semianticlockwise

**Answer:** B) Anticlockwise

**Explanation:**

Orientations in polar graphs are measured anticlockwise for positive angles and clockwise for negative angles.

**134. It is said to be encircled if a point lies inside the ____ path.**

- Closed
- Open
- Line
- None

**Answer:** A) Closed

**Explanation:**

It is said to be encircled if a point lies inside the closed path.

**135. It is said to be ____ by a closed path if it lies to the right of a path when traversed in a certain direction.**

- Enclosed
- Enslaved
- Opened
- None

**Answer:** A) Enclosed

**Explanation:**

It is said to be enclosed by a closed path if it lies to the right of a path when traversed in a certain direction.

**136. What is/are the advantages of the Nyquist plot?**

- Control system stability can be determined by it.
- In terms of time delay, it is superior to the root locus.
- An open-loop transfer function can be found by measuring its frequency response.
- All of the above

**Answer:** D) All of the above

**Explanation:**

The advantages of the Nyquist plot are -

- Control system stability can be determined by it.
- In terms of time delay, it is superior to the root locus.
- An open-loop transfer function can be found by measuring its frequency response.

**137. What is/are the disadvantages of the Nyquist plot?**

- Mathematical techniques are used in it.
- System stability cannot be determined by it.
- On the right side of the s-plane, it does not provide the exact number of poles.
- All of the above

**Answer:** D) All of the above

**Explanation:**

The disadvantages of the Nyquist plot are -

- Mathematical techniques are used in it.
- System stability cannot be determined by it.
- On the right side of the s-plane, it does not provide the exact number of poles.

**138. Control devices, such as ____ controllers, monitor, and control plant output based on the actual value and desired value.**

- Automatic
- Semi-automatic
- Non-automatic
- None

**Answer:** A) Automatic

**Explanation:**

Control devices, such as automatic controllers, monitor, and control plant output based on the actual value and desired value.

**139. Using an automatic controller, the system's deviation is determined and controlled to reduce it to ____ with a control signal.**

- 0
- Small value
- Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

Using an automatic controller, the system's deviation is determined and controlled to reduce it to 0 or a small value with a control signal.

**140. The ____ action describes how an automatic controller generates a control signal.**

- Control
- Uncontrolled
- Semi-control
- None

**Answer:** A) Control

**Explanation:**

The control action describes how an automatic controller generates a control signal.

**141. According to their control action, industrial controllers can be classified as follows:**

- ON - OFF Controller
- Proportional Controller
- Integral Controller
- All of the above

**Answer:** D) All of the above

**Explanation:**

According to their control action, industrial controllers can be classified as follows:

- ON - OFF Controller
- Proportional Controller
- Integral Controller

**142. With proportional control action, the output of the controller (M) is continuously related to the ____ signal E (deviation).**

- Passive error
- Acting error
- Both A and B
- None of the above

**Answer:** B) Acting error

**Explanation:**

With proportional control action, the output of the controller (M) is continuously related to the acting error signal E (deviation).

**143. A control system's compensators fall into the following category/ies:**

- Lead
- Lag
- Lag-lead
- All of the above

**Answer:** D) All of the above

**Explanation:**

A control system's compensators fall into the following categories:

- Lead
- Lag
- Lag-lead

**144. Control systems produce outputs with phase leads by using ____ compensators.**

- Lead
- Lag
- Lag-lead
- None

**Answer:** A) Lead

**Explanation:**

Control systems produce outputs with phase leads by using lead compensators.

**145. In a control system, the phase ____ is compensated by the lag compensator.**

- Lead
- Lag
- Lag-lead
- None

**Answer:** B) Lag

**Explanation:**

In a control system, the phase lag is compensated by the lag compensator.

**146. What is the full form of GCP?**

- Gain Circular Point
- Gain Crossover Point
- Gain Crossover Plugin
- Gain Crossover Pin

**Answer:** B) Gain Crossover Point

**Explanation:**

The full form of GCP is Gain Crossover Point.

**147. When a gain crossover point is reached, a ____ is added in phase lead.**

- Phase angle
- Phase lag
- Phase lag-lead
- None

**Answer:** A) Phase angle

**Explanation:**

When a gain crossover point is reached, a phase angle is added to the phase lead.

**148. When the phase margin is lagged, the error constant is ____, but the phase margin remains the same.**

- Increased
- Decreased
- Both A and B
- None of the above

**Answer:** A) Increased

**Explanation:**

When the phase margin is lag, the error constant is increased, but the phase margin remains the same.

**149. What is/are the result(s) of phase lead?**

- In the area near the gain crossover point, the phase shift increases due to the addition of a phase angle.
- As a result, the system gains more gain at a higher frequency.
- Dynamic response and system response are improved.
- All of the above

**Answer:** D) All of the above

**Explanation:**

The results of phase lead are -

- In the area near the gain crossover point, the phase shift increases due to the addition of a phase angle.
- As a result, the system gains more gain at a higher frequency.
- Dynamic response and system response are improved.

**150. What is/are the result(s) of phase lag?**

- As a result, the crossover point for gain is lowered.
- As a result, the system gains less.
- Stable state error is reduced and damping is improved.
- All of the above

**Answer:** D) All of the above

**Explanation:**

The results of phase lag are -

- As a result, the crossover point for gain is lowered.
- As a result, the system gains less.
- Stable state error is reduced and damping is improved.

**151. What is/are the advantage(s) of phase lead?**

- System dynamic response is improved, resulting in faster response times.
- As a result, the bandwidth of the system is increased.
- High-pass filtering is what it does.
- All of the above

**Answer:** D) All of the above

**Explanation:**

The advantages of phase lead are -

- System dynamic response is improved, resulting in faster response times.
- As a result, the bandwidth of the system is increased.
- High-pass filtering is what it does.

**152. What is/are the advantage(s) of phase lag?**

- Reducing steady-state error improves system performance at a steady state.
- Noise at high frequencies is suppressed by it.
- Providing high gain at lower frequencies, it acts as a low-pass filter.
- All of the above

**Answer:** D) All of the above

**Explanation:**

The advantages of phase lag are -

- Reducing steady-state error improves system performance at a steady state.
- Noise at high frequencies is suppressed by it.
- Providing high gain at lower frequencies, it acts as a low-pass filter.

**153. What is/are the disadvantages of phase lead?**

- There is a tendency for noise to be produced.
- The amplifier gain needs to be increased.
- Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

The disadvantages of phase lead are -

- There is a tendency for noise to be produced.
- The amplifier gain needs to be increased.

**154. What is/are the disadvantages of phase lag?**

- The RC (resistor-capacitor) value must be large.
- Transient responses are decreased as a result.
- Both A and B
- None of the above

**Answer:** C) Both A and B

**Explanation:**

The disadvantages of phase lag are -

- The RC (resistor-capacitor) value must be large.
- Transient responses are decreased as a result.

**155. To increase transient response speed, phase ____ is used.**

- Lead
- Lag
- Lag-lead
- Lead-lag

**Answer:** A) Lead

**Explanation:**

To increase transient response speed, phase lead is used.

**156. Steady-state error is reduced by phase ____.**

- Lag
- Lead
- Lag-lead
- Lead-lag

**Answer:** A) Lag

**Explanation:**

Steady state error is reduced by the phase lag.

**157. In the lag-lead compensator, phase lag is produced when applying a signal to one frequency region and phase ____ when applying a signal to the other.**

- Lead
- Lag
- Lag-lead
- None

**Answer:** C) Lag-lead

**Explanation:**

In the lag-lead compensator, phase lag is produced when applying a signal to one frequency region and phase lead when applying a signal to the other.

**158. What is the advantage of a Lag-lead compensator?**

- Whenever steady-state performance is required, the combination of these two may be used (lag-lead compensator).
- Whenever a fast response is required, the combination of these two may be used (lag-lead compensator).
- Whenever fast response and steady-state performance are required, the combination of these two may be used (lag-lead compensator).
- Whenever fast response and steady-state performance are not required, the combination of these two may be used (lag-lead compensator).

**Answer:** C) Whenever fast response and steady-state performance are required, the combination of these two may be used (lag-lead compensator).

**Explanation:**

The advantage of a Lag-lead compensator is that whenever fast response and steady-state performance are required, the combination of these two may be used (lag-lead compensator).

**159. What is/are the application(s) of a lag-lead compensator?**

- Laser frequency stabilization, satellite control, robotics, and LCDs (Liquid Crystal Displays) are some of the applications of this technology.
- Analog control systems rely heavily on it.
- By reducing steady-state errors and improving bandwidth, transient response, and transient response, the parameters of the system can be improved.
- All of the above

**Answer:** D) All of the above

**Explanation:**

The applications of lag-lead compensator are -

- Laser frequency stabilization, satellite control, robotics, and LCDs (Liquid Crystal Displays) are some of the applications of this technology.
- Analog control systems rely heavily on it.
- By reducing steady-state errors and improving bandwidth, transient response, and transient response, the parameters of the system can be improved.

**160. ____ variable analysis is the process of determining a system's state.**

- State
- Transient
- Translation
- Transition

**Answer:** A) State

**Explanation:**

State variable analysis is the process of determining a system's state.

**161. What is/are the advantage(s) of state space techniques?**

- Linear and nonlinear systems, time-variant and time-invariant, can be analyzed and characterized using this technique.
- Where Laplace transformation is not feasible, this is an easier method to apply.
- 'N' equations of the first order can be used to express nth-order differential equations.
- All of the above

**Answer:** D) All of the above

**Explanation:**

The advantages of state space techniques are -

- Linear and nonlinear systems, time-variant and time-invariant, can be analyzed and characterized using this technique.
- Where Laplace transformation is not feasible, this is an easier method to apply.
- 'N' equations of the first order can be used to express nth-order differential equations.

**162. Digital computer computation is suitable for State Space Techniques since it is a time ____ method.**

- Domain
- Non-domain
- Semi-domain
- None

**Answer:** A) Domain

**Explanation:**

Digital computer computation is suitable for State Space Techniques since it is a time domain method.

**163. We can predict the behavior of a control system based on a set of variables known as the ____.**

- State
- Transient
- Transition
- Translation

**Answer:** A) State

**Explanation:**

We can predict the behavior of a control system based on a set of variables known as the state.

**164. In the state variable analysis, ____, and representations of state variables are included.**

- State vectors
- State spaces
- Equations
- All of the above

**Answer:** D) All of the above

**Explanation:**

In the state variable analysis, state vectors, state spaces, equations, and representations of state variables are included.

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