CLASS: B.S. ELECTRONICS
13A/ 206
St. JOSEPH’S COLLEGE (AUTONOMOUS) TIRUCHIRAPPALLI – 620 002
SEMESTER EXAMINATIONS – APRIL 2013
TIME: 3 Hrs.
MAXIMUM MARKS: 100
SEM
SET
PAPER CODE
TITLE OF THE PAPER
VI
2010
10UEL630303B
CONTROL SYSTEM
SECTION – A
Answer all the questions:
20 x 1 = 20
Choose the correct answer:
1.
The automatic controller consists of _______.
a) Error detector, Amplifier and controller
c) Amplifier and filter
b)
d)
Actuator, plant, sensor
Error detector, sensor unit
2.
The mathematical representation of the ramp signal is _______.
a) r(t) = A u(t)
b) r(t) = A/s
c) r(t) = At2 / 2
d) r(t) = At
3.
The value of steady state error depends on _______.
a) Type number and output signal
b)
c) Type number and input signal
d)
4.
Input and output signal
Type number
Bode plot, Polar plot and Nichols plot are usually drawn for _____.
a) Closed loop system
b) automatic control system
c) feed back system
d) open loop system
5.
The relative stability indicates the _______ of the system to stable region.
a) closeness
b) steady state error
c) time domain
d) frequency domain
Fill in the blanks:
6.
The open loop system can be modified as closed loop system by providing a _______.
7.
The response of the system as _______ is called steady state response.
8.
The steady state error is a measure of system _______.
9.
Bode plot is the _______ technique is used for frequency response analysis.
10.
The term _______ refers to the stable working condition of a control system.
State True or False:
11.
The mason’s gain formula is used to determine the transfer function of the system from the
block diagram reduction technique.
12.
Test signals are simple function of Time.
13.
The proportional controller produces and output signal which is proportional to error signal.
14.
The transfer function of complicated systems can be determined by its time response.
15.
The denominator polynomial of closed loop transfer function is called characteristic equation
of the system.
Match the following:
16.
Functional block
-
a) BIBO stability
17.
Damping ratio
-
b) Kp
18.
Position error constant
-
c) 
19.
Gain margin
-
d) Summing operation
20.
Linear relaxed system
- e) Kg
SECTION – B
Answer all the questions:
21.
a.
5 x 4 = 20
Draw and explain the force balance equation for ideal dashpot and ideal spring element.
OR
22.
b.
State the applications of Potentiometers with necessary diagram.
a.
What is the importance of test signals? State the mathematical expression of step and
ramp signal.
OR
23.
b.
What is the order of a system? Explain.
a.
What is PI controller? Explain the closed loop transfer function of PI controller.
OR
24.
b.
Explain steady state error.
a.
Define Phase margin and Gain margin.
OR
25.
b.
What is Bode plot? And give the advantages of bode plot.
a.
State the point that the roots of characteristic equation based on locations.
OR
b.
Using Routh criterion, determine the locations of the roots of the given characteristic
equation, s4 + 8s3 + 18s2 + 16s + 5 = 0 and Comment on the stability of the
system.
SECTION – C
Answer any FOUR questions:
26.
4 x 15 = 60
Write the different equations governing the mechanical system shown in figure and determine
the transfer function.
X1
K1
X
B
M
M11
M2
f(t)
K
B1
B2
27.
Explain the response of first order system for unit step input.
28.
Obtain the response of unity feedback system whose open loop transfer function is G(s) =
4/s(s+5).
29.
List out the frequency domain specifications.
30.
Construct Routh array and determine the stability of the system whose characteristics equation
is s6 + 2s5 + 8s4 + 12s3 + 20s2 + 16s + 16 = 0. Also determine the number of roots lying
on right half of s-plane, left half of s-plane and on imaginary axis.
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