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ECE :: Automatic Control Systems

  1. The polar plot of transport lag is a unit circle.

  2. A.
    True
    B.
    False

  3. The given figure shows a hybrid servosystem. The components 1, 2, 3, 4 are respectively

  4. A.
    amplifier, demodulator, dc servomotor and load
    B.
    demodulator, amplifier, dc servomotor and load
    C.
    demodulator, dc servomotor, amplifier and load
    D.
    amplifier, dc servomotor, demodulator and load

  5. For the signal flow graph of the given figure consider the following statements

    1. It has three forward paths
    2. It has three individual loops
    3. It has two non touching loops
    Out of above the correct statements are

  6. A.
    1, 2, 3
    B.
    1, 2
    C.
    2, 3
    D.
    1, 3

  7. For the transport lag G(jω) = e-jωT, the polar plot is

  8. A.
    a semi circle
    B.
    a circle
    C.
    a unit circle
    D.
    none of the above

  9. Consider the following statements:

    1. The positiveness of coefficients of characteristic equation is necessary as well as sufficient condition for stability of first and second order systems.
    2. The positiveness of coefficients of characteristic equation ensures negativeness of real roots but is not sufficient condition for stability of third and higher order systems.
    Out of above statements:

  10. A.
    only 1 is correct
    B.
    both 1 and 2 are correct
    C.
    only 2 is correct
    D.
    both are wrong

  11. Assertion (A): The time response, usually, is slower with lag compensation.

    Reason (R): The natural undamped frequency and bandwidth are increased.

  12. A.
    Both A and R are correct and R is correct explanation of A
    B.
    Both A and R are correct but R is not correct explanation of A
    C.
    A is correct but R is wrong
    D.
    R is correct but A is wrong

  13. For the factor the corner frequency is

  14. A.
    0.5 rad/sec
    B.
    1 rad/sec
    C.
    2 rad/sec
    D.
    4 rad/sec

  15. For a second order system, the position of poles is shown in the given figure. This system is

  16. A.
    undamped
    B.
    overdamped
    C.
    underdamped
    D.
    critically damped

  17. A lag compensator provides attenuation in

  18. A.
    very low frequency range
    B.
    low frequency range
    C.
    high frequency range
    D.
    none of the above

  19. A stepper motor is essentially

  20. A.
    a synchronous motor
    B.
    induction motor
    C.
    dc motor
    D.
    either (b) or (c)