Principles of Control Systems - Dec 2012
Electronics Engineering (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.
Answer any four of the following:-
1 (a) For the block diagram shown, find the transfer function between Y(s) and W(s).
(5 marks) 1 (b) List the type of damping of second order system with location of poles.(5 marks) 1 (c) Compare time and frequency responses and explain the correlation between them.(5 marks) 1 (d) With an example, determine the relative stability of system using Routh stability criterion.(5 marks) 1 (e) Define gain margin and phase margin. Explain how to find them for magnitude v/s phase plot.(5 marks) 2 (a) Draw the signal flow graph of the given block diagram and obtain the closed loop transfer function using masons gain formula.
(10 marks) 2 (b) From the given state space model, obtain the transfer function.(10 marks) 3 (a) Sketch the root locus of the system shown and sketch the stability.
(10 marks) 3 (b) A unity feedback control system is characterized by open loop transfer function
Determine its Transient response for a unit step input. Evaluate Maximum overshoot and peak time.
(10 marks) 4 (a) Sketch the bode plot for the following transfer function and determine the system gain crossover frequency, phase crossover frequency, gain margin and phase margin.
(10 marks) 4 (b) Draw the Nyquist plot and assess the stability of closed loop system whose open loop transfer function is
(10 marks) 5 (a) Sketch the polar plots for the following:
(10 marks) 5 (b) A unity feedback system has
(i) Determine the steady state error if K=1.5.
(ii) Also find the minimum value of K if the steady state error ? 0.1 for a unit ramp input.
(10 marks) 6 (a) Draw the circuit diagrams of basic lag and lead compensating networks derive the transfer function.(10 marks) 6 (b) Explain the principle of operation and characteristics of a two phase servo motor.(10 marks)
Write shorts notes on the following:-
7 (a) Synchros.(7 marks) 7 (b) M and N circles.(7 marks) 7 (c) Effect of feedback on sensitivity and stability.(7 marks)