PTU B.Tech ECE 4th Semester May 2019 57021 LINEAR CONTROL SYSTEMS Question Papers

PTU Punjab Technical University B-Tech May 2019 Question Papers 4th Semester Electronic and Communication Engineering (ECE)

Roll No.
Total No. of Pages : 03
Total No. of Questions : 09
B.Tech.(EIE) (2011 & Onwards) (Sem.?4)
LINEAR CONTROL SYSTEMS
Subject Code : IC-204
M.Code : 57021
Time : 3 Hrs. Max. Marks : 60
INSTRUCTIONS TO CANDIDATES :
1.
SECTION-A is COMPULSORY consisting of TEN questions carrying T WO marks
each.
2.
SECTION-B contains FIVE questions carrying FIVE marks each and students
have to attempt any FOUR questions.
3.
SECTION-C contains T HREE questions carrying T EN marks each and students
have to attempt any T WO questions.

SECTION-A
1.
Answer briefly :



a. What do you mean by servomechanism? Explain.

b. What do you mean by steady state error? Explain.

c. Define settling time and maximum overshoot.


d. Discuss the significance of time constant in first order system.


e. List the advantages and disadvantages of Routh-Hurwitz criterion.


f. Discuss the importance of Asymptotes in root locus.


g. Discuss the various test input signals used for time domain analysis.


h. Why compensation is required? Explain.

i. Discuss the importance of synchro in control system.


j. Discuss the importance of Laplace transform in control system.


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SECTION-B
2. Differentiate :

a) Linear and non-linear systems

b) Open and closed loop systems

c) Time variant and time invariant systems
3.
Using Mathematical Modelling, find the x2(s)/f(t) of the system shown below :
f1
K1
M1
M
x1
f2
K2
M
M2 2
x2
f(t)

4.
What do you mean by order of a system? Determine the transient and steady state response
of first order system when unit step input is applied.
5.
Sketch the bode plot for the system when open loop transfer function is given by
50
G(s)
.
(s 2) (s 1)
6.
Explain in detail A.C. and D.C. tachometers used in control systems.

SECTION-C
50
7.
Design a phase lag compensating network for G(s)
.
s(1 0.1s) (1 0.2s)

to meet the following specifications : Kv = 30 sec?1, P.M. 40?

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8.
a) Represent the following set of equations by a signal flow graph and determine the

overall gain relating x5 and x1.



x2 = a x1 + fx2



x3 = b x2 + ex4



x4 = c x3 + hx5



x5 = d x4 + gx2


b) Find whether the system shown below is stable or not?

4



2
s(s 1) (s 3) (s 4s 8)
9.
Discuss the following :

a) Root Locus

b) Servo motors










NOTE : Disclosure of Identity by writing Mobile No. or Making of passing request on any
page of Answer Sheet will lead to UMC against the Student.

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This post was last modified on 04 November 2019