Control Systems Mid - II, November - 2014

1.The frequency at which angle of G(jw) H (jw) = -1800 is called the
  • Gain cross over frequency
  • Phase cross over frequency
  • Gain margin
  • Phase margin
Answer: B
2.For the pole factor 5/[s+5] the corner frequency is
  • 42009
  • -5
  • 5
  • -0.2
Answer: C
3.A polar plot intersects the unit circle at (-1 + j0). The gain margin of the system is
  • -1 dB
  • 0 dB
  •  dB
  • cannot be estimated
Answer: B
4.A polar plot crosses the real axis at (-1 + j0) point. The phase margin of the system is
  • O0
  • -10
  • -1800
  • +1800
Answer: A
5.In q (s) – plane the Nyquist plot is symmetrical about the
  • Imaginary axis
  • Real axis
  • Origin
  • None of these
Answer: B
6.Lag compensation is preferred when ______ response is to be improved
  • Transient
  • Steady state
  • Both (a) & (b)
  • None of these
Answer: B
7.The compensator required to improve both the transient & steady state response of the system is
  • Lag
  • Lead
  • Lag – Lead
  • None of these
Answer: C
8.The state variable approach is applicable to
  • Only linear time invariant systems
  • Linear time invariant as well as time varying systems
  • Linear as well as nonlinear systems
  • All systems
Answer: D
9.X (t) = A x (t) + Bu (t) is called the
  • System equation
  • State equation
  • State transition equation
  • None
Answer: B
10.The Eigen values of the state model are same as
  • Open loop poles
  • Closed loop poles
  • Both (a) & (b)
  • None
Answer: B
11.% peak over shoot depend only on _______________
Answer: ζ
12.Bandwidth and Risetime are ____________ proportional to ζ (Zeta)
Answer: Inversely
13.The frequency at which the low frequency and high frequency asymptotes of the Bode plot meet is called the ___________
Answer: Corner frequency
14.The Nyquist stability criterion is based on the _______________
Answer: Principle of Argument
15.The nyquist stability criterion provides information on ________ stability as well as __________ stability of a system.
Answer: Absolute, relative
16.Lead compensation is preferred when ____________ response is to be improved.
Answer: Transient
17.The lag network acts as a __________ filter.
Answer: Low pass
18.For a lead compensator a __________ is nearer to the origin.
Answer: Zero
19.The transfer function approach _____________ the initial conditions whereas the state variable approach _________ the initial conditions.
Answer: Neglects, considers
20.The state model of a system is not unique whereas the _________ of a system is unique.
Answer: Transfer function.