Download GTU (Gujarat Technological University Ahmedabad) B.Tech/BE (Bachelor of Technology/ Bachelor of Engineering) 2020 Winter 4th Sem 3141708 Control Theory Previous Question Paper
Seat No.: ________
Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE- SEMESTER?IV (NEW) EXAMINATION ? WINTER 2020
Subject Code:3141708 Date:11/02/2021
Subject Name:Control Theory
Time:02:30 PM TO 04:30 PM Total Marks:56
Instructions:
1. Attempt any FOUR questions out of EIGHT questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
MARKS
Q.1 (a) Differentiate between open loop system and closed loop systems
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(b) Define Transfer function. Find the impulse response of a system whose
04
transfer function is G=1/(S+4)
(c) Find the overall transfer function of RLC circuit with output across
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capacitor.
Q.2 (a) Write mason's gain formula.
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(b) Difference between signal flow graph and block diagram
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representation of system
(c) For the hovering systems given by
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Q.3 (a) Define 1. Source node, 2. Loop, 3. Sink node
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(b) Find the transfer function for the following system
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(c) Find the mathematical model of the mechanical network
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Q.4 (a) What is analogous of all variables in mechanical network in force-
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current analogy?
(b) Explain liquid level systems in brief
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(c) What is state space model? Define states. Derive the expression for
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converting state model to transfer function?
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Q.5 (a) Find the polar plot of G=1/S
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(b) What is Bode plot. What should be the input to the system to obtain
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bode plot. What are the units of scales used for plotting bode plot
(c) Sketch Bode plots of a unity feedback control system having open-
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loop transfer function as given below. The magnitude plot of this
function should be an exact one and not an approximation. Find the
64(s 2)
GM and PM G(s)
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s(s 0.5)(s 3.2s 64)
Q.6 (a)
0 1
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Find the eigen values for system represented by A
2 3
(b) Write the rules for drawing root locus
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(c) Sketch the root locus for an open loop transfer function
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Q.7 (a) Explain standard test signals
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(b) For the system G=25/S2+4S+25, find the natural frequency, damping
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ratio. Depending on the damping ratio, describe the system
(c) A unity feedback control system's open loop transfer function is
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Using Routh criterion, calculate the range of k for the system to be
stable. If the value of k=1, comment on stability.
Q.8 (a) For the closed loop system G=(S+1)(S+3)/S3(S+1)(S+3), find the
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following 1. Order, 2. Type, 3. characteristic equation
Check the system stability for system whose characteristic equation is
(b) given by S4+8S3+16S+5=0
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(c) Draw unit step response of a second order control systems. Describe
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all specification in detail.
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This post was last modified on 04 March 2021