Question Paper: Control Systems : Question Paper Dec 2013 - Electronics & Telecomm. (Semester 4) | Mumbai University (MU)
0

Control Systems - Dec 2013

Electronics & Telecomm. (Semester 4)

TOTAL MARKS: 80
TOTAL TIME: 3 HOURS
(1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Assume data if required.
(4) Figures to the right indicate full marks.
1 (a) Define sensitivity of a control system. How can we reduce the sensitivity of a closed loop system.(5 marks) 1 (b) Explain Hurwitz stability criterion and its disadvantages.(5 marks) 1 (c) Define the following terms related to second order system subjected to unit step input.
(i) Rise time
(ii) Peak time.
(iii) Peak overshoot
(iv) Delay time.
(v) Settling time.
(5 marks)
1 (d) What are the advantages of a Nyquist plot.(5 marks) 2 (a) If the second order control system has transfer function
F(s) = s2 + 24s + 9.
If a step input is applied to it, determine time domain specifications. Also sketch time response.
(10 marks)
2 (b) Find the range of K to make the system stable for a unity feedback system.
(10 marks)
3 (a) Determine the transfer functions C/R1 and C/R2 from the given system below. Also find C/R.
(10 marks)
3 (b) Find the transfer function of the following system using signal flow graph.
(10 marks)
4 (a) Draw the root locus for the system with
G(s)H(s) = K/[s(s+3)(s+6)]. Obtain the value of K when ?=0.6 from root locus. Also determine the value of K for marginal stability and critical damping.
(10 marks)
4 (b) For a unity feedback system: G(s) = 200/[s(s+8)] and r(t)=2t, determine steady state error. If it is desired to reduce the existing error by 5%, find new value of gain of system.(10 marks) 5 (a) A unity feedback system has a loop gain
G(s)H(s)=60/[(s+4)(s2+2s+5)]. Determine the system stability using Nyquist plot.
(10 marks)
5 (b) Compare open loop control system and closed loop control system with at least 3 examples.(10 marks) 6 (a) Use Bode plot to determine the frequency response of system. H(s)=1 and
(10 marks)
6 (b) A unity feedback control system has
G(s) = K/[(s+4)3]. Determine the range of K for system stability.
(10 marks)

Write shorts notes any two of the following:-

7 (a) Stepper motor construction and its applications in control system.(10 marks) 7 (b) State variable model with an example.(10 marks) 7 (c) Error compensation techniques.(10 marks)