JNTU Kakinada B-Tech 3-1 RT31043 I CONTROL SYSTEMS R13 April 2018 Question Paper

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Code No: RT31043
III B. Tech I Semester Supplementary Examinations, May- 2018
CONTROL SYSTEMS (Common to Electronics and Communication Engineering and Electronics and Instrumentation
Engineering)Time: 3 hours Max. Marks: 70
Note: 1. Question Paper consists of two parts (Part-A and Part-B)2. Answering the question in Part-A is compulsory
3. Answer any THREE Questions from Part-B
(Normal and semi & polar graph sheet are to be supplied)~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PART ?A
1 a) Explain the limitations of closed loop system over open loop system. [3M]
b) Explain the advantages of signal flow graph over block diagram representation. [4M]
c) What are Effects of proportional integral systems? [4M]
d) What are effects by adding poles in the root locus? [4M]
e) Define gain margin? [4M]
f) What is Obsevability? [3M]
PART -B
2 a) Explain the temperature control system concepts using open loop as well as closed
loop systems
[8M]
b)What is signal flow graph and explain the steps to reduce the system flow graph using
mason gain formulae.
[8M]
3 a) Derive the transfer function of field controlled DC Servo motor. [8M]
b)Obtain the transfer function C(s)/R(s) by using Block diagram algebra for the figure
given below:
[8M]
4 a) For unity feedback system having open loop transfer function as

. Determine error constants K
p
, K
v
and K
a
?
[8M]
b)A unity feedback control system has an open loop transfer function,

Find the rise time, percentage overshoot, peak time and settling time for a step
input of 12 units.
1 of 2

[8M]
R13
SET – 1
R13
SET – 1
|”|”|||”|”’|||’|

Code No: RT31043
III B. Tech I Semester Supplementary Examinations, May- 2018
CONTROL SYSTEMS (Common to Electronics and Communication Engineering and Electronics and Instrumentation
Engineering)Time: 3 hours Max. Marks: 70
Note: 1. Question Paper consists of two parts (Part-A and Part-B)2. Answering the question in Part-A is compulsory
3. Answer any THREE Questions from Part-B
(Normal and semi & polar graph sheet are to be supplied)~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PART ?A
1 a) Explain the limitations of closed loop system over open loop system. [3M]
b) Explain the advantages of signal flow graph over block diagram representation. [4M]
c) What are Effects of proportional integral systems? [4M]
d) What are effects by adding poles in the root locus? [4M]
e) Define gain margin? [4M]
f) What is Obsevability? [3M]
PART -B
2 a) Explain the temperature control system concepts using open loop as well as closed
loop systems
[8M]
b)What is signal flow graph and explain the steps to reduce the system flow graph using
mason gain formulae.
[8M]
3 a) Derive the transfer function of field controlled DC Servo motor. [8M]
b)Obtain the transfer function C(s)/R(s) by using Block diagram algebra for the figure
given below:
[8M]
4 a) For unity feedback system having open loop transfer function as

. Determine error constants K
p
, K
v
and K
a
?
[8M]
b)A unity feedback control system has an open loop transfer function,

Find the rise time, percentage overshoot, peak time and settling time for a step
input of 12 units.
1 of 2

[8M]
R13
SET – 1
R13
SET – 1
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Code No: RT31043

5 a) The characteristics equation of feedback control system is


+3

++2+40 . determine the range of K for which system is
stable.
[8M]
b) Plot the root locus pattern of a system whose forward path transfer function is

.
[8M]
6 a) Find the Gain margin and phase margin of the system if the open loop transfer
function is


[8M]
b) The open loop transfer function of a feedback control system is given by

Plot the Nyquist plot and show that the closed loop system is stable if
=2 .
[8M]
7 a) What is lag compensator? [4M]
b)A unity feedback system has an open loop transfer function,


.design a suitable lag compensator so that phase margin is 40
0
and the steady state
error for ramp input is less than or equal to 0.2.
[12M]
*****

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