# Control Systems Expected MCQ PDF 1 For Coal India Limited (CIL) MT Exam 2017

1)   Which
terminology deals with the excitation or stimulus applied to the system
from an external source for the generation of an output?

a. Input signal
b. Output signal
c. Error signal
d. Feedback signal

2)   Which among the following is not an advantage of an open loop system?

a. Simplicity in construction & design
b. Easy maintenance
c. Rare problems of stability
d. Requirement of system recalibration from time to time

 ANSWER: Requirement of system recalibration from time to time

3)   Which notation represents the feedback path in closed loop system representation?

a. b(t)
b. c(t)
c. e(t)
d. r(t)

4)   Which among the following represents an illustration of closed loop system?

a. Automatic washing machine
b. Automatic electric iron
d. Electric hand drier

5)   How is an output represented in the control systems?

a. r(t)
b. c(t)
c. x(t)
d. y(t)

6)   The output is said to be zero state response because ______conditions are made equal to zero.

a. Initial
b. Final
d. Impulse response

7)   Basically,
poles of transfer function are the laplace transform variable values
which causes the transfer function to become ___________

a. Zero
b. Unity
c. Infinite
d. Average value

8)   By equating the denominator of transfer function to zero, which among the following will be obtained?

a. Poles
b. Zeros
c. Both a and b
d. None of the above

9)   The output signal is fed back at the input side from the _________point

a. Summing
b. Differential
c. Take-off
d. All of the above

10)   In a
parallel combination, the direction of flow of signals through blocks in
parallel must resemble to the main _______

a. Forward
b. Feedback
c. Opposite
d. Diagonal

11)   While shifting a take-off point after the summing point, which among the following should be added?

a. Summing point in series with take-off point
b. Summing point in parallel with take-off point
c. Block of reciprocal transfer function
d. Block of inverse transfer function

 ANSWER: Summing point in series with take-off point

12)   Consider the assertions related to block diagram. Which among them represents the precise condition?
A. Block diagram is used for analysis & design of control system.
B. Block diagram also provides the information regarding the physical construction of the system.

a. A is true, B is false
b. A is false, B is true
c. Both A & B are true
d. Both A & B are false

 ANSWER: A is true, B is false

13)   In a signal flow graph, nodes are represented by small _____

a. Circles
b. Squares
c. Arrows
d. Pointers

14)   According to
signal flow graph, which among the following represents the
relationship between nodes by drawing a line between them?

a. Branch
b. Self-loop
c. Semi-node
d. Mesh

15)   Which type of node comprises incoming as well as outgoing branches?

a. Source node
b. Sink node
c. Chain node
d. Main node

16)   Where are the dummy nodes added in the branch with unity gain?

a. At input & output nodes
b. Between chain nodes
c. Both a and b
d. None of the above

 ANSWER: At input & output nodes

17)   According to the property of impulse test signal, what is the value of an impulse at t = 0?

a. Zero
b. Unity
c. Infinite
d. Unpredictable

18)   What is the value of parabolic input in Laplace domain?

a. 1
b. A/s
c. A/s2
d. A/s3

19)   Which among the following is/are an/the illustration/s of a sinusoidal input?

a. Setting the temperature of an air conditioner
b. Input given to an elevator
c. Checking the quality of speakers of music system
d. All of the above

 ANSWER: Checking the quality of speakers of music system

20)   If a system
is subjected to step input, which type of static error coefficient
performs the function of controlling steady state error?

a. Position
b. Velocity
c. Acceleration
d. Retardation

21)   On the basis of an output response, into how many parts can the s-plane be divided?

a. 2
b. 3
c. 4
d. 6

22)   If the
complex conjugate poles are located at RHP, what would be the nature of
corresponding impulse response?

a. Exponential
b. Damping oscillations
c. Increasing amplifier
d. Constant amplitude oscillations

23)   Which among the following are solely responsible in determining the speed of response of control system?

a. Poles
b. Zeros
c. Speed of input
d. All of the above

24)   If a pole is located at s = -5 in left-hand plane (LHP), how will it be represented in Laplace domain?

a. 1/ s + 5
b. 1/ s – 5
c. s/ s + 5
d. s/ s – 5

25)   In second order system, which among the following remains independent of gain (k)?

a. Open loop poles
b. Closed loop poles
c. Both a and b
d. None of the above

26)   Root locus specifies the movement of closed loop poles especially when the gain of system ________

a. Remains constant
b. Exhibit variations
c. Gives zero feedback
d. Gives infinite poles

27)   Which condition is used to verify the existence of a particular point on the root locus?

a. Amplitude
b. Frequency
c. Magnitude
d. Angle

28)   While specifying the angle and magnitude conditions, angles are added whereas magnitudes get ________

a. Subtracted
b. Multiplied
c. Divided
d. All of the above

29)   The
magnitude & phase relationship between _________input and the steady
state output is called as frequency domain.

a. Step
b. Ramp
c. Sinusoidal
d. Parabolic

30)   If a linear system is subjected to an input r(t) = Asin(ωt), what output will be generated?

a. c(t) = B sin (ωt + Φ)
b. c(t) = B cos (ωt + Φ)
c. c(t) = B tan (ωt + Φ)
d. c(t) = B cot (ωt + Φ)

 ANSWER: c(t) = B sin (ωt + Φ)

31)   Which unit is adopted for magnitude measurement in Bode plots?

a. Degree
b. Decimal
c. Decibel
d. Deviation

32)   In an octave frequency band, the ratio of f2 / f1 is equivalent to ________

a. 2
b. 4
c. 8
d. 10

33)   In polar plots, what does each and every point represent w.r.t magnitude and angle?

a. Scalar
b. Vector
c. Phasor
d. Differentiator

34)   In polar plots, if a pole is added at the origin, what would be the value of the magnitude at Ω = 0?

a. Zero
b. Infinity
c. Unity
d. Unpredictable

35)   Conventional control theory is applicable to ______ systems

a. SISO
b. MIMO
c. Time varying
d. Non-linear

36)   State space analysis is applicable even if the initial conditions are _____

a. Zero
b. Non-zero
c. Equal
d. Not equal

37)   If an error signal e(t) of an ON-OFF controller is found to be greater than zero, what would be its output?

a. 10%
b. 50%
c. 80%
d. 100%

38)   Which time
is responsible for introducing an error in the temperature regulation of
applications associated with ON-OFF controllers?

a. Rise time
c. Switching time
d. Decay time

39)   Which
controller has the potential to eliminate/overcome the drawback of
offset in proportional controllers?

a. P-I
b. P-D
c. Both a and b
d. None of the above

40)   In P-I controller, what does an integral of a function compute?

a. Density of curve
b. Area under the curve
c. Volume over the curve
d. Circumference of curve

var pfHeaderImgUrl = ”;var pfHeaderTagline = ”;var pfdisableClickToDel = 0;var pfHideImages = 0;var pfImageDisplayStyle = ‘right’;var pfDisablePDF = 0;var pfDisableEmail = 0;var pfDisablePrint = 0;var pfCustomCSS = ”;var pfBtVersion=’1′;(function(){var js,pf;pf=document.createElement(‘script’);pf.type=’text/javascript’;pf.src=’//cdn.printfriendly.com/printfriendly.js’;document.getElementsByTagName(‘head’).appendChild(pf)})(); 1. yibeltal September 7, 2017