Control System Objectives Part 11
101 . Root locus diagrams exhibit which one of the following? The poles of the transfer function for a set of parameter values.
Question 202 to 203 refer to data given below:
202 . A closed loop control system has an open loop gain of 100. Its feedback loop has a gain of 0.005. Its sensitivity for positive feedback is 0.67.
203 . Sensitive for negative feedback is 2.0.
Question 204 to 208 refer to data given below:
A model for a mass damper system, with linear approximations, relates the applied force u(t) to the output velocity y(t) using the transfer function
H(s) = 𝑌(𝑠)𝑈(𝑠) = 6𝑠+2
204 . The system’s time constant T describing the time required for the step response to reach 63 % of its steady state value 0.5.
205 . Transient behavior of this system is a decreasing exponential
206 . If as system is viewed as a processor of sinusoidal input signals to generate the frequency response, it would be a low pass filter.
207 . What is the value of system bandwidth? 2.
208 . If a sinusoidal input force with frequency exactly at the system bandwidth is applied, what is the value of the gain factor? 𝟑√𝟐𝟐 .
209 . Which of the following is not true for Signal Flow Graph? Branch directing from node yk to yj represent the dependence of variable yj upon k and vice versa.
210 . What is the Laplace transform of a step function of a magnitude a?𝒂𝒔 .
211 . The advantage of Nyquist stability test is: its applicability to experimental results of frequency response to open loop system, its ability to predict its closed loop stability from open loop results & its ability to indicate how to stabilize an unstable system (all of the above).
212 . Which of the following can be extended to systems which are time varying? State model representatives.
213 . The unity circle of Nyquist plot corresponds to the 0 dB line for the Bode plot for all frequencies.
Question 214 to 217 refer to data given below:
A chemical reactor with input flow u(t) and output concentration j(t)is modelled as a linear system with impulse response
h(t) = (4 + 8t) e-2t for t>= 0.
214 . The number of state variables needed to represent this system is 2.
215 . Transients in this system are critically damped.
216 . The steady state unit step response has magnitude 4.
217 . The complete solution for the unit step response contain an exponential term of the form Cert where the number r is –2.
218 . The slope in Bode plot is expressed as (per unit change in low ꙍ) -6 dB/octave.
Question 219 to 226 refer to data given below:
A unity feedback system has an open loop transfer function 𝐺(𝑠)=25𝑠(𝑠+8)
219 . The damping ratio is 0.8.
220 . The percentage peak overshoot is 1.5 %.