KIIT University 2008 B.Tech Electronics and Tele-Communication Engineering CONTROL SYSTEM - Question Paper
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CONTROL SYSTEM
------5TH SEMESTER 2008---
v-B.Tech Regular & RaoLi CS-I EE 504 (E&EE, E&TC)
FIFTH SEMESTER EXAMINATION-2008 CONTROL SYSTEM-1 [ EE 504 ]
Time: 3 Flours
Answer any SIX questions including Question No.l which is compulsory.
The figures in the margin indicate full marks.
Candidates are required to give their answers in their own words as far as practicable and of all parts of a question should be answered at one place only.
1. a) What is regenerative feedback and where it is used? [2 x 10
b) Define phase cross over frequency and gain cross over frequency.
c) How to control the effect of disturbance signals in a feedback system?
d) What are the effects of derivative control on damping ratio, maximum overshoot and steady state error?
e) What is the effect of addition of a pole and a zero to the closed loop transfer function?
f) What is the necessary and sufficient condition for stability using Routh method?
g) What do you mean by a polar plot?
h) What do you mean by the angle of departure and how to calculate? Where it is used?
i) Define phase margin. Calculate gain margin for open loop
transfer function of a unity feedback control system --Q.
j) Define velocity error constant. Find out position error constant
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(1) KI!T- U/20Q8/A utumn End Semester Examination-2008 |
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a) Find out C/R using block reduction method. {Ki | ||
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rn |  |
b) Write the differential equation of the following mechanical system. Draw the analogous electrical circuit based on force vs voltage analogy. fC U _ K, |
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zero friction |
3. a) Find the transfer function of the following electrical system. L
v(t)
v,(t)
b) Determine the transfer function of the signal flow graph using Masons loop gain formula.
a
Q
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a) The open loop transfer function of a unity feedback system is given by
where K and T are positive constant
G(s) =
.(Ts + 1)
By what factor should the amplifier gain (K) be reduced so that the peak overshoot of unit step response of the system is reduced from 60% to 30%.
b) Determine the range of K for which system will be stable for the given system. Also find out the no. of roots of the characteristic equation that are in the right half of the s-plane for K=0.5.
[5
R(s)
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->C(s) | ||||||||||
5. a) Block diagram of a positional control system is shown below. [5
(i) In the absence of derivative feedback (K=0), determine damping ratio of the system for amplifier gain KA=5. Also find the steady state error to unit ramp input.
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(ii) Find suitable values of parameters KA & Kt so that damping ratio of the system is increased to 0.7 without affecting the steady state error as obtained in part(i). |
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b) A unity feedback system is characterised by an open loop [5 |
transfer function G(s) = c. Determine the gain K s(s + 4)
(3)
fIT-U/2008/Autumn End Semester Examination-2008
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6. a) Draw the root loci diagram of the following system for 0<k<oo. |
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b) A unity feedback system has open loop transfer function -j
so that the system will have a damping ratio of 0.25. For this value ofK, determine the settling time, peak overshoot and time to peak overshoot for a unit step i/p.
G(s) = 7*7 Draw Nyquist plot for the system. s(4s + 1Xs +1)
Obtain gain margin and phase margin.
7. a) Sketch the Bode plot for the transfer function
G(s) H(s) = -. Determine the system w w s2(s + 50Xs + 2)
gain cross over frequency, phase cross over frequency, gain margin and phase margin. Also determine the value of K for a phase margin of 45.
b) The open loop transfer function of a unity feedback control system is given by
Gfe)-... KP + 2s)
W (s + 2Xs + 5>2'
Determine the values of K which will cause sustained oscillations in a closed loop system.
8. Write short notes (any two)
a) gear train
b) PID control
c) Synchros
KIIT-JJ/2008/Autumn End Semester Examination-2008
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Attachment: |
| Earning: Approval pending. |
