Bengal Engineering and Science University 2006 B.E Electrical Engineering Control System-I - Question Paper
The ques. paper is with the attachment in pdf format.
Ex/BESUS/ EE-603/06 B.E. (EE) Part-III 6th Semester Examination, 2006
Time : 3 hours Full Marks : 100
Use separate answerscript_for each half. Answer SIX questions, taking THREE _ from each half. Two marks are reserved_for neatness in each half.
FIRST HALF
1. a) Define transfer function. State the significance of transfer function. State its
limitations.
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K.
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b) Derive the transfer function of the network shown in Fig.-1.
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Fig.-l
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[8+8]
2. a) Draw the block diagram of the circuit
shown in Fig.-2.
b) Determine the transfer function of the block diagram shown in Fig.-3.
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[8+8] |
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Fig.-3 | |
i
3. a) Draw the Signal Flow graph of Fig.3.
b) Determine the time response of a first order system with step and ramp inputs. Define time constant. [8+8]
Short notes (any two) : [8+8]
a) Type and order of system
b) Static Error Co-efficient
c) Synchronous system
d) Function of demodulators and its realisation with diodes.
6. a) How can you assess relative stability by gain margin and phase margin?
b) i) Draw the Nyquist Plot for a unity feedback system with open loop transfer function:
ii) Now find range of K for stability of the closed loop system. [4+10+2]
7. a) Draw the complete root loci for 0 < K < oo for the unity feedback system with open loop transfer function :
G(s) = K(s + 6)
Now that solution to 4A = 0 gives: s = -6.8, -4 j 0.5,-1
ds
b) What is a 'centroid' and a 'break away point' in a root locus? [14+2]
8. a) Draw the Bode Plot for the transfer function G(s) given in 7(a) taking K= 10. Find
the Gain margin and Phase margin of the system from the Bode Plot.
b) What are M-circles? What is their use? [12+4]
9. a) What is a Nichol's chart?
b) Deduce for a standard second order system with unity feedback the expression of the resonance peak and resonance frequency as a function of the damping ratio and natural frequency of oscillation.
c) Highlight the constructional features and operation of a two phase A.C. Servomotor and a closed-loop application of it. [2+7+7]
10. a) Define cut-off frequency and bandwidth.
b) Describe a simplified operation of a tacho generator.
c) Deduce the transfer function of a d.c. servomotor and mention its difference from a d.c. motor.
d) What is a strictly proper system? [2+6+7+1]
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| Earning: Approval pending. |
