University of Mumbai 2008-5th Sem B.E Electrical and Electronics Engineering Control System-I - Question Paper

Control System-I Sem V June 2008

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(REVISED COURSE)

[Total Marks : 100

(3 Hours)

N.B.: (1) Question No. 1 is compulsory,

(2)    Attempt any four questions from remaining.

(3)    All questions carries equal marks.

1. Attempt any four :

(a) Find the voltage transfer function for Figure. R\    9*'L-

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T

(b)    Derive the expression for peak time t_p.

(c)    Find transfer function by Masons gain formula for figure.

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(d) Figure shows lines of constant peak time t_p, constant overshoot %M_p, and constant settling time t_, identify them and write your answer.

(e) Find the state space representation for the figure assuming that the outputs are the currents flowing through R1 and R2.

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2. (a) Find transfer function G(s) = xsJ/Ffs), for the translational mechanical system shown in figure.

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(b) Find transfer function by block diagram reduction for figure.

3. (a) Open loop T. F. of a unity feed back system is given by

^{G(S) =} S(1+ST)

(i)    Find by what factor the gain K should be multiplied so that over shoot reduces from 80% to 20%.

(ii)    Find by what factor gain K should be multiplied so that damping Ration increases from 0-2 to 0-6.

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(b) For a unity feed back system G(s) =

(i)    If r(t) = 4t and k = 2 find steady state error.

(ii)    If it is desired to have steady state error to be 0-2. Find the corresponding value of K.

(iii)    Find the steady state error if input is r (t) = 2 + 6 t and K = 10.

4. (a) Open loop transfer function of a unity feed back system is given by

G(s)

(i)    Determine the relation between K and T for stable system.

(ii)    Find the relation between K and T for all roots of the system to lie on left of S = - 1 line.

(iii)    Plot the stable region K verses T in both cases.

(b) Determine the resonant frequency, resonant peak and bandwidth for the system given by transfer function

^c(s) 5

s² + 2s + 5

5. (a) Sketch the root locus for the figure.

(b) Explain how k_p, k_v, and k_a can be calculated from Bode plot.

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800(s + 2)

6. (a) Draw the Bode plot for G(s) H(s) = g

s-(s + 10)(s + 40)

(b) Find the transfer function from the Bode magnitude plot shown in figure.

Write short notes on any three :

(a)    Stepper motor

(b)    N/quist stability criterion

(c)    M-N circles

(d)    Explain the force voltage analogy in control systems with suitable example.

7.

Attachment: university-of-mumbai-2008-b-e-electrical-and-electronics-engineering-51158-1.pdf

Earning:   Approval pending.