Seat No.: _____                                            Enrolment No.
______
             GUJARAT TECHNOLOGICAL UNIVERSITY
                  M.E Sem-I Remedial Examination April 2010
Subject code: 710703                   Subject ame: Modern Control System
Date:08 /04 /2010                      Time: 12.00 noon  02.30 pm
                                       Total Marks: 60
Instructions:
       1. Attempt all questions.
       2. Make suitable assumptions wherever necessary.
       3. Figures to the right indicate full marks.
Q:1 a) Explain the concept of state, state variables and state model             (06)
     b) Obtain the state equations for the field controlled D.C motor shown in
        fig 1(b)                                                               (06)
                   Rf                                        Ia (Constant)
                      If                                      m,Jm,fm
        Ef                       Lf             Kf
                                         fig 1(b)
Q:2 a) List the steps for constructing state space representation using canonical
       variables.                                                                 (06)
      b) How the state variables method can be used to represent discrete-time
        system?                                                                  (06)
                                        OR
      b) Explain : Controllability                                             (06)
Q:3 a) Explain : State Transition Matrix                                         (06)
    b) List the properties of state transition matrix.                           (06)
                                           OR
Q:3 a) Explain the concept of Transfer Matrix for state space representation. (06)
     b) Define : Observability                                                 (06)
Q:4 a) Find the inverse of matrix.                                               (06)
  .
                  1 3 3
          A=      1 4 3
                  1 3 4
                                                                                    1
     b) Find the rank of the matrix.                                         (06)
         A=      3 -1 2
                -6 2 4
                -3 1 2
                                          OR
Q:4 a) Express the matrix A as a sum of a symmetric and a skew  symmetric
       matrix; where                                                         (06)
                           4 2 -3
                   A=      1 3 -6
                          -5 0 -7
    b) List various types of matrices with illustration.                     (06)
Q:5 a) Solve the following different equation by matrix method.              (10)
        d2x / dt2 - 5dx/dt     + 6x = 0 , x(0) = 1, x(0) = 2
    b) Is the rank of a matrix , affected by elementary transformation?      (02)
                                          OR
Q:5 a) By neat diagram explain :  Asymptotic stability                     (04)
    b) Explain : Liapunovs stability criteria                               (08)
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