# Control System MCQ Electrical Engineering

50 Questions 30 Mins

### About Control System

Following are some of the multiple choice questions on the Control System with answers that will help the students in developing their knowledge.

## Control System MCQ

### 1. The frequency and time domain are related through which of the following?

• Laplace Transform and Fourier Integral
• Laplace Transform
• Fourier Integral
• Either (B) or (C)

### 2. Zero initial condition for a system means

• input reference signal is zero
• zero stored energy
• ne initial movement of moving parts
• system is at rest and no energy is stored in any of its components

• e(t)
• c(t)
• r(t)
• s(t)

### 4. A phase lag lead network introduces in the output

• lag at all frequencies
• lag at high frequencies and lead at low frequencies
• lag at low frequencies and lead at high frequencies
• none of the above

### 5. The initial response when tne output is not equal to input is called

• Transient response
• Error response
• Dynamic response
• Either of the above

### 6. When the initial conditions of a system are specified to be zero it implies that thesystem is

• at rest without any energy stored in it
• working normally with reference input
• working normally with zero reference input
• at rest but stores energy

### 7. Hydraulic torque transmission system is analog of

• amplidyne set
• resistance-capacitance parallel circuit
• motor-generator set
• any of the above

• charge
• current
• inductance
• resistance

### 9. An increase in gain, in most systems, leads to

• smaller damping ratio
• larger damping ratio
• constant damping ratio
• none of the above

• true
• false

### 11. When the number of poles is equal to the number of zeroes, how many branches of root locus tends towards infinity?

• 1
• 2
• equal to number of zeroes
• none of the above

### 12. When human being tries to approach an object, his brain acts as,

• an error measuring device
• a controller
• an actuator
• an amplifier

### 13. The effect of error damping is to

• provide larger settling lime
• delay the response
• reduce steady state error
• any of the above

### 14. A differentiator is usually not a part of a control system because it

• reduces damping
• reduces the gain margin
• increases input noise
• increases error

### 15. Which among the following plays a crucial role in determining the state of dynamic system?

• state variables
• state vector
• state space
• state scalar

### 16. Which among the following are the interconnected units of state diagram representation?

• scalars
• integrator
• all of the mentioned

### 17. Which of the following are the not characteristics of the closed loop systems?

• it does not compensate for disturbance
• it reduces the sensitivity of plant-parameter variations
• it does not involve output measurements
• it does not has the ability to control the system transient response

### 18. Which mechanism in control engineering implies an ability to measure the state by taking measurements at output?

• controllability
• observability
• differentiability

### 19. Which one of the following is not the property of root loci?

• the root locus is symmetrical about imaginary axis
• they start from the open loop poles and terminate at the open loop zeroes
• the breakaway points are determined from dk/ds = 0
• segments of the real axis are the part of the root locus if and only is the total number of real poles and zeroes to their right is od

• 0
• 0.707
• 1
• infinite

### 21. The addition of open loop zero pulls the root loci towards:

• the left and therefore system becomes more stable
• the right and therefore system becomes unstable
• imaginary axis and therefore system becomes marginally stable
• the left and therefore system becomes unstable

### 22. What is the number of the root locus segments which do not terminate on zeroes?

• the number of poles
• the number of zeroes
• the difference between the number of poles and zeroes
• the sum of the number of poles and the number of the zeroes

### 23. Which one of the following are correct? The root locus is the path of the roots of the characteristic equation traced out in the s- plane?

• as the input of the system is changed
• as the output of the system is changed
• as a system parameter is changed
• as the sensitivity is changed

• true
• false

### 25. A system is said to be____________if it is possible to transfer the system state from any initial state to any desired state in finite interval of time.

• controllable
• observable
• cannot be determined
• controllable and observable

### 26. With feedback___________reduces.

• system stability
• system gain
• system stability and gain
• none of the mentioned

### 27. _____________directly converts temperature into voltage.

• Thermocouple
• Potentiometer
• Gear train
• LVDT

### 28. In a control system integral error compensation_____________steady state error

• increases
• minimizes
• does not have any effect on
• all of the mentioned

### 29. A system is said to be______________if it is possible to transfer the system state from any initial state to any desired state in finite interval of time.

• controllable
• observable
• cannot be determined
• controllable and observable

• i
• a
• e-at
• -eat

### 31. State model representation is possible using____________

• physical variables
• phase variables
• canonical state variables
• all of the mentioned

• zero
• non-zero
• equal
• not equal

• siso
• mimo
• time varying
• non-linear

### 34. An amplidyne can give which of the following characteristics ?

• Constant current
• Constant voltage
• Constant current as well as constant voltage
• Constant current, constant voltage and constant power

### 35. Technique is not applicable to nonlinear system ?

• Nyquist Criterion
• Quasi linearization
• Functional analysis
• Phase-plane representation

### 36. Insertion of negative feedback in control system affects:

• the transient response to vanish uniformly
• the transient response to decay very fast
• no change in transient response
• the transient response decays at slow rate

• instability
• bandwidth
• overall gain
• distortion

### 38. Which among the following constitute the state model of a system in addition to state equations?

• input equations
• output equations
• state trajectory
• state vector

### 39. Stability of a system implies that :

• small changes in the system input does not result in large change in system output
• small changes in the system parameters does not result in large change in system output
• small changes in the initial conditions does not result in large change in system output
• all of the above mentioned

• center
• focus point
• stable node

• center
• focus point
• stable node

• centre
• focus point
• stable node

### 43. Servomotor:

• armature controlled fhp dc motor
• a pair of synchronous transmitter and control transformer
• tach generator
• amplidyne

### 44. Consider a system if represented by state space equation and x1 (t) =x2 (t), then the system is:

• controllable
• uncontrollable
• observable
• unstable

### 45. Amplifier:

• armature controlled fhp dc motor
• a pair of synchronous transmitter and control transformer
• tach generator
• amplidyne

### 46. Kalman’s test is for :

• observability
• controllability
• optimality
• observability and controllability

### 47. Kalman’s test is for :

• observability
• controllability
• optimality
• observability and controllability

• -1b+d
• c(zi-a)-1
• (zi-a)-1z
• (zi-a)-1

### 49. A transfer function of the system does not have pole-zero cancellation? Which of the following statements is true?

• system is neither controllable nor observable
• system is completely controllable and observable
• system is observable but uncontrollable
• system is controllable and unobservable

• center
• focus point