Consider the following statements with reference to frequency-domain approaches to analysis of feedback to control system
A. 1 and 2 only
B. 1 and 3 only
C. 2 and 3 only
D. 1, 2 and 3
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The transfer function of a plant is T ( s ) = ( s + 5 ) ( s 2 + s + 1 ) 5 .
A. ( s + 5 ) ( s + 1 ) 1
B. ( s + 5 ) ( s + 1 ) 5
C. s 2 + s + 1 5
D. s 2 + s + 1 1
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The correct sequences of steps needed to improve system stability is:
A. Insert derivative action, use negative feedback, reduce gain
B. Reduce gain, use negative feedback, insert derivative action
C. Reduce gain, Insert derivative action, use negative feed back
D. Use negative feedback, reduce gain, and insert derivative action
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The phase-lead network function G C ( s ) = s + a T 1 s + T 1 ,
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Identify the matrix that can be a state transition matrix.
A. \phi = \left[ {\begin{array}{*{20}{c}}
{{e^{ - t}}}&0\\
1&{{e^{ - 2t}}}
\end{array}} \right]
B. \phi = \left[ {\begin{array}{*{20}{c}}
{{e^t}}&t\\
1&{2{e^{ - t}}}
\end{array}} \right]
C. \phi = \left[ {\begin{array}{*{20}{c}}
{{e^t} + {e^{ - t}}}&0\\
0&{2{e^{ - t}}}
\end{array}} \right]
D. \phi = \left[ {\begin{array}{*{20}{c}}
{{e^{ - t}}}&0\\
0&{{e^{ - 2t}}}
\end{array}} \right]
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Consider the following information regards open loop frequency response of a unity feedback system
ω |G(j)| ∠G(j)
2
7.5
-118°
3
4.8
-130°
4
3.15
-140°
5
2.25
-150°
6
1.70
-157°
8
1.00
-170°
10
0.64
-180°
The gain and phase margin of the system are respectively:
A. 0 dB, -180°
B. 3.86 dB, -180°
C. 0 dB, -10°
D. 3.86 dB, 10°
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A control system has G ( s ) H ( s ) = s ( s + 3 ) ( s + 4 ) K ( s + 1 ) .
A. between s = -1 and s = -3
B. between s = 0 and s = -4
C. between s = -3 and s = -4
D. towards left of s = -4
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The unit step response of a particular control system is given by c(t) = 1 - 10e-t . Then its transfer function is:
A. s + 1 10
B. s + 1 s − 9
C. s + 1 1 − 9 s
D. s ( s + 1 ) 1 − 9 s
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Due to derivative control, the steady-state error is
A. ratio control reduced
B. cascade control increased
C. split range control not effected
D. inferential control made zero
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The characteristic equation of a closed loop system is given by s4 + 6s3 + 11s2 + 6s + k = 0
A. 0 < k < 10
B. k > 10
C. -∞ ≤ k < ∞
D. 0 < k ≤ ∞
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The characteristics equation of a closed loop control system is given as s2 + 4s + 16 = 0. The resonant frequency in radian/sec of the system is
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What is the number of root-locus segments which do not terminate on zeros?
A. The number of poles
B. The number of zeros
C. The difference between the number of poles and the number of zeros
D. The sum of the number of poles and the number of zeros
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Consider the feedback system shown in the figure. The Nyquist plot of G(s) is also shown. Which one of the following conclusions is correct?
A. G(s) is an all-pass filter
B. G(s) is a strictly proper transfer function
C. G(s) is a stable and minimum-phase transfer function
D. The closed-loop system is unstable for sufficiently large and positive k
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If the initial conditions for a system are inherently zero, what does it physically mean?
A. The system is at rest but stores energy
B. The system is working but does not store energy
C. The system is at rest or no energy is stored in any of its parts
D. The system is working with zero reference input
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Which of the following statements with respect to the stability of a control system is true?
A. Only 1 and 3 are true
B. Only 1, 2 are true
C. Only 1, 2 and 3 are true
D. Only 4 is true
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In the Bode diagram of H ( s ) = 1 + 10 s ,
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A process is controlled by a PID controller. The sensor has high measurement noise. How can this effect be reduced?
A. By use of a bandwidth limited derivative term
B. By use of proportional and derivative terms in the forward path
C. By use of high proportional band
D. By use of low integral gain
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In a servo-system, the device used for providing derivative feedback is known as:
A. Synchro
B. Servomotor
C. Potentiometer
D. Tachogenerator
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The type of system shown in the bode plot here is:
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In a feedback system, feedback factor of 0.1 is used with forward gain of 10. The sensitivity of the system with respect to the feedback element is
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