Kerala University 2009 B.Tech Applied Electronics and Instrumentation Sixth Semester , (2003 Scheme) Branch : Applied Electronics 03-605 : CONTROL SYSTEM THEORY (A) - Question Paper

Illllllllllllllll    (Pages : 3)    8019

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Sixth Semester B.Tech. Degree Examination, December 2009

(2003 Scheme)

Branch : Applied Electronics 03-605 : CONTROL SYSTEM THEORY (A)

Max. Marks : 100

PART - A

Answer all questions. Each question carries 4 marks.

1. Find the transfer function of a system represented by the differential equation

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PART - B

Answer two questions from each Module. Each question carries 10 marks.

Module - I

11.    Derive the mathematical model for a liquid level system and then obtain the transfer function.

12.    For the system represented by the following set of equations, find the transfer

function ^(s) using signal flow graph. x(s)

ⁱ⁾    y = y1 + p3x

ii)    y1=-a1y1 + y2 +fcx

iii)    y2 = -a2y1 + frx

13.    Sketch the root locus plot for the feed back system whose open loop transfer

K

function G(s) H(s) =--

s(s + 2) (s¹ + 2s + 2

Module - II

14.    Consider the characteristic equation s² + 2s³ + (4 + K) s² + 11s + 13 = 0. Using the Rouths stability criterion, determine the range of K for stability.

15.    Construct Bode magnitude and phase diagrams for

100(0.1s +1)

G(s) H(s) =-₂-

s(s +1) (0.01s +1)

Also comment on the closed loop stability of the system.

s + 2

16. Sketch the Nyquist plot for G(s) H(s) =

(s + 1)(s -1)

Module - III

17.    The forward path transfer function of a certain unity negative feedback control

n K system is G(s) =-

s(s +1)(s + 25)

The system has to satisfy the following specification

a)    Phase margin > 30

b)    Gain margin > 18 dB

c)    Steady state error for unit ramp input < 20. Design a suitable lead compensator.

18.    Sketch Bode diagram of PID controller. Also give an application for feed forward control system.

19.    Discuss about Zero-placement approach to improve response characteristics.

1

   Derive the mathematical model for a thermal system and find the transfer function.

2

   What is relative stability and absolute stability ?

3

   State and explain Masons gain formula for signal flow graphs.

Attachment: kerala-university-2009-b-tech-applied-electronics-and-instrumentation-39588-1.pdf

Earning:   Approval pending.