ECE-320, Practice Quiz #6 Problems 1 and 2 refer to the following root locus plot. 1) Is it possible to find a value of k so that -6 is a closed loop pole? -12 -10 -8 -6 -4 -2 0-10-50510Root LocusReal AxisImaginary Axis a) Yes b) No 2) When k = 623 two poles of the closed loop system are purely imaginary. In order for the system to remain stable a) 0 b) k > 623 c) k > 0 d) k < 0 623k<<Problems 3 and 4 refer to the following root locus plot -12 -10 -8 -6 -4 -2 0 2 4 6 8-5-4-3-2-1012345Root LocusReal AxisImaginary Axis 3) Is it possible to find a value of k so that -5 is a closed loop pole? a) Yes b) No 4) When k = 0.795 two poles of the closed loop system are purely imaginary. In order for the system to remain stable a) 0 < k < 0.795 b) k > 0.795 c) k > 0 d) k < 0Problems 5-9 refer to the following system 2(1)ss+100( 10)( 20)ss+++ - The closed loop poles of the system are at 2.91 11.1j−± and -15.2 5) The best estimate of the settling time is a) 41 seconds b) 420 seconds c) 415.2 seconds d) 42.91 seconds 6) The best estimate of the steady state error for a unit step input is a) 1101 b) 1100 c) 0 d) ∞ 7) The best estimate of the steady state error for a unit ramp input is a) 0 b) c) ∞1100 d) 1101 8) Now we add a lag compensator to change the steady state error for a ramp input, as shown below 2(1)ss+szsp++ 100( 10)( 20)ss+++ - If we want the steady state error for a unit ramp input to be 0.001 and we choose z = 0.1, what should p be? a) 1 b) 0.1 c) 0.01 d) 0.0019) With the lag compensator in the system (as shown in problem 8) do we expect the settling time of the system to a) increase b) decrease c) remain the same Problems 10-12 refer to the following root locus plot for a unity feedback system with a plant and a controller. 10) Based on this root locus plot, the best estimate of the poles of the closed loop system are -20 -18 -16 -14 -12 -10 -8 -6 -4 -2 0-60-40-200204060Root Locus Editor for Open Loop 1 (OL1)Real AxisImag Axis a) 0, -2, and -20 b) -4+18j, -4-18j, -14 11) Is this a type one system? a) yes b) no 12) Is this a stable system? a) yes b) noProblems 13-15 refer to the following root locus plot for a unity feedback system with a plant and a controller. 13) Based on this root locus plot, the best estimate of the poles of the closed loop system are -8 -7 -6 -5 -4 -3 -2 -1 0-4-3-2-101234Root Locus Editor for Open Loop 1 (OL1)Real AxisImag Axis a) -1+j3, -1-3j b) -4+3j, -4-3j, -0.5 14) Is this a type one system? a) yes b) no 15) Is this a stable system? a) yes b) no16) Assume we use a lag compensator properly to achieve the desired steady state error for a ramp input. We should expect the settling time of the system to a) increase b) decrease c) remain the same 17) Assume we add a lag compensator to change the velocity error, as shown below 20(1)ss+szsp++ 5( 1)10ss++ + - If we want the steady state error for a unit ramp input to be 0.001 and we choose z = 0.1, what should p be? a) 1 b) 0.1 c) 0.01 d) 0.001 Answers: 1-b, 2-a, 3-a, 4-b, 5-d, 6-c, 7-c, 8-c, 9-c, 10-b, 11-a, 12-a, 13-b, 14-a, 15-a 16-c,
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