Control Systems Test Questions Set 2

1)   Which among the following controls the speed of D.C. motor?

a. Galvanometer
b. Gauss meter
c. Potentiometer
d. Tachometer
Answer  Explanation  Related Ques

ANSWER: Tachometer

Explanation:
No explanation is available for this question!


2)   Into which energy signal does the position sensor convert the measured position of servomotor in servomechanisms?

a. Mechanical
b. Electrical
c. Thermal
d. Light
Answer  Explanation  Related Ques

ANSWER: Electrical

Explanation:
No explanation is available for this question!


3)   What is the value of steady state error in closed loop control systems?

a. Zero
b. Unity
c. Infinity
d. Unpredictable
Answer  Explanation  Related Ques

ANSWER: Zero

Explanation:
No explanation is available for this question!


4)   A good control system should be sensitive to __________

a. Internal disturbances
b. Environmental parameters
c. Parametric variations
d. Input signals (except noise)
Answer  Explanation  Related Ques

ANSWER: Input signals (except noise)

Explanation:
No explanation is available for this question!


5)   For the transfer function given below, where does the zero of the system lie?

G(s) = 5s -1 / s2 + 5s + 4


a. s = -1 & s = -1/4
b. s = -4 & s = -1
c. s = 1/5
d. s = -1/5
Answer  Explanation  Related Ques

ANSWER: s = 1/5

Explanation:
No explanation is available for this question!


6)   If a signal is passed through an integrator, it _____the amplitude of noise signal.

a. Enhances
b. Reduces
c. Stabilizes
d. Factorizes
Answer  Explanation  Related Ques

ANSWER: Reduces

Explanation:
No explanation is available for this question!


7)   Laplace transform of an impulse response is regarded as  _____function of the system

a. Analytic
b. Parabolic
c. Transfer
d. Hypothetical
Answer  Explanation  Related Ques

ANSWER: Transfer

Explanation:
No explanation is available for this question!


8)   The fundamental function of a tachometer is the conversion of angular _______ into voltage

a. Velocity
b. Displacement
c. Acceleration
d. Current
Answer  Explanation  Related Ques

ANSWER: Velocity

Explanation:
No explanation is available for this question!


9)   If finite number of blocks are connected in series or cascade configuration, then how are the blocks combined algebraically?

a. By addition
b. By multiplication
c. By differentiation
d. By integration
Answer  Explanation  Related Ques

ANSWER: By multiplication

Explanation:
No explanation is available for this question!


10)   Associative law for summing point is applicable only to those summing points which are __________connected to each other.

a. Directly
b. Indirectly
c. Orthogonally
d. Diagonally
Answer  Explanation  Related Ques

ANSWER: Directly

Explanation:
No explanation is available for this question!


11)   For the elimination of feedback loops, the derivation based on transfer function of ______ loop is used.

a. Open
b. Closed
c. Both a and b
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Closed

Explanation:
No explanation is available for this question!


12)   In block diagram representation, what do the lines connecting the blocks, known as?

a. Branches
b. Nodes
c. Datums
d. Sources
Answer  Explanation  Related Ques

ANSWER: Branches

Explanation:
No explanation is available for this question!


13)   In a signal flow graph method, how is an overall transfer function of a system obtained?

a. Poisson's equation
b. Block diagram reduction rules
c. Mason's equation
d. Lagrange's equation
Answer  Explanation  Related Ques

ANSWER: Mason's equation

Explanation:
No explanation is available for this question!


14)   While solving signal flow graph using Mason's gain equation, what does the second letter in two subscript notation of 'L' stand for?

a. Serial number of loop
b. Parallel number of loop
c. Number of touching loops
d. Number of non-touching loops
Answer  Explanation  Related Ques

ANSWER: Number of non-touching loops

Explanation:
No explanation is available for this question!


15)   For which systems are the signal flow graphs applicable?

a. Causal
b. Invertible
c. Linear time invariant system
d. Dynamic
Answer  Explanation  Related Ques

ANSWER: Linear time invariant system

Explanation:
No explanation is available for this question!


16)   Two loops are said to be non-touching only if no common ______exists between them.

a. Loop
b. Feedback path
c. Branch
d. Node
Answer  Explanation  Related Ques

ANSWER: Node

Explanation:
No explanation is available for this question!


17)   In time domain system, which response has its existence even after an extinction of transient response?

a. Step response
b. Impulse response
c. Steady state response
d. All of the above
Answer  Explanation  Related Ques

ANSWER: Steady state response

Explanation:
No explanation is available for this question!


18)   Which among the following is represented by a parabolic input signal?

a. Position
b. Force
c. Velocity
d. Acceleration
Answer  Explanation  Related Ques

ANSWER: Acceleration

Explanation:
No explanation is available for this question!


19)   Type 0 systems are unsuitable  ___________

a. For ramp inputs
b. If the input is parabolic in nature
c. Both a and b
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Both a and b

Explanation:
No explanation is available for this question!


20)   If a type 0 system is subjected to step input, what is its effect on steady state error?

a. It increases continuously
b. It remains constant
c. It decreases monotonically
d. It gets subjected to another input
Answer  Explanation  Related Ques

ANSWER: It remains constant

Explanation:
No explanation is available for this question!


21)   Consider that the pole is located at origin and its laplace representation is 1/s. What would be the nature of pole response?

a. Rising exponential
b. Decaying exponential
c. Sinusoidal
d. Constant value
Answer  Explanation  Related Ques

ANSWER: Constant value

Explanation:
No explanation is available for this question!


22)   In accordance to relative stability, the settling time exhibits inversely proportional nature to ________parts of roots

a. Real positive
b. Real negative
c. Imaginary positive
d. Imaginary negative
Answer  Explanation  Related Ques

ANSWER: Real negative

Explanation:
No explanation is available for this question!


23)   In Routh array, if zero is found in the first column, then by which term it needs to be replaced?

a. δ
b. η
c. σ
d. ε
Answer  Explanation  Related Ques

ANSWER: ε

Explanation:
No explanation is available for this question!


24)   In a second order system, if the damping ratio is greater than equal to '1', then what would be the nature of roots?

a. Imaginary
b. Real and equal
c. Real but not equal
d. Complex conjugate
Answer  Explanation  Related Ques

ANSWER: Real but not equal

Explanation:
No explanation is available for this question!


25)   For drawing root locus, the angle of asymptote yields the direction along which _________branches approach to infinity.

a. p + z
b. p - z
c. p / z
d. p x z
Answer  Explanation  Related Ques

ANSWER: p - z

Explanation:
No explanation is available for this question!


26)   Which point on root locus specifies the meeting or collision of two poles?

a. Centroid
b. Break away point
c. Stability point
d. Anti-break point
Answer  Explanation  Related Ques

ANSWER: Break away point

Explanation:
No explanation is available for this question!


27)   What should be the nature of root locus about the real axis?

a. Assymetric
b. Symmetric
c. Exponential
d. Decaying
Answer  Explanation  Related Ques

ANSWER: Symmetric

Explanation:
No explanation is available for this question!


28)   If the system is specified by open loop transfer function G(s)H(s) = k / s(s+3) (s + 2), how many root loci proceed to end at infinity?

a. 2
b. 3
c. 5
d. 6
Answer  Explanation  Related Ques

ANSWER: 3

Explanation:
No explanation is available for this question!


29)   Which plots in frequency domain represent the two separate plots of magnitude and phase against frequency in logarithmic value?

a. Polar plots
b. Bode plots
c. Nyquist plots
d. All of the above
Answer  Explanation  Related Ques

ANSWER: Bode plots

Explanation:
No explanation is available for this question!


30)   How is the sinusoidal transfer function obtained from the system transfer function in frequency domain?

a. Replacement of 'jω' by 's'
b. Replacement of 's' by 'ω'
c. Replacement of 's' by 'jω'
d. Replacement of 'ω' by 's'
Answer  Explanation  Related Ques

ANSWER: Replacement of 's' by 'jω'

Explanation:
No explanation is available for this question!


31)   According to the principle of log-scales, if the ratio between two points is same, then the two points get ________equally.

a. United
b. Separated
c. Multiplexed
d. Mixed
Answer  Explanation  Related Ques

ANSWER: Separated

Explanation:
No explanation is available for this question!


32)   If a pole is located at origin, how does it get represented on the magnitude plot?

a. -10 log (ω) dB
b. -20 log (ω) dB
c. -40 log (ω) dB
d. -60 log (ω) dB
Answer  Explanation  Related Ques

ANSWER: -20 log (ω) dB

Explanation:
No explanation is available for this question!


33)   Due to an addition of pole at origin, the polar plot gets shifted by  ___ at ω = 0?

a. -45°
b. -60°
c. -90°
d. -180°
Answer  Explanation  Related Ques

ANSWER: -90°

Explanation:
No explanation is available for this question!


34)   Consider the system represented by the equation given below. What would be the total phase value at ω = 0?
200/ [s3 (s + 3) (s + 6) (s + 10)]


a. -90°
b. -180°
c. -270°
d. -360°
Answer  Explanation  Related Ques

ANSWER: -270°

Explanation:
No explanation is available for this question!


35)   Which among the following are the interconnected units of state diagram representation?

a. Scalars
b. Adders
c. Integrators
d. All of the above
Answer  Explanation  Related Ques

ANSWER: All of the above

Explanation:
No explanation is available for this question!


36)   Which among the following plays a crucial role in determining the state of dynamic system?

a. State variables
b. State vector
c. State space
d. State scalar
Answer  Explanation  Related Ques

ANSWER: State variables

Explanation:
No explanation is available for this question!


37)   In P-D controller, the derivative action plays a significant role in increasing _______ of response.

a. Time
b. Distance
c. Speed
d. Volume
Answer  Explanation  Related Ques

ANSWER: Speed

Explanation:
No explanation is available for this question!


38)   In addition to storage instructions, PLC controls __________

a. Logic sequence timing
b. Counting
c. Arithmetic operations
d. All of the above
Answer  Explanation  Related Ques

ANSWER: All of the above

Explanation:
No explanation is available for this question!


39)   Which is the correct sequence of operational steps necessary for proper operation of an elevator (lift) control mechanism?

1. Up switch
2. Stop switch
3. Down switch
4. Start switch


a. 1-2-3-4
b. 2-1-4-3
c. 4-2-1-3
d. 3-1-2-4
Answer  Explanation  Related Ques

ANSWER: 4-2-1-3

Explanation:
No explanation is available for this question!


40)   How many digital inputs are present in PLCs?

a. 4
b. 8
c. 16
d. 32
Answer  Explanation  Related Ques

ANSWER: 16

Explanation:
No explanation is available for this question!