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ECE :: Automatic Control Systems

  1. The system in the given figure

  2. A.
    will be unstable due to the presence of positive feedback in the inner loop
    B.
    may be stabilized by the negative feedback outer loop
    C.
    can never be stable
    D.
    will always be stable

  3. The units of thermal capacitance are

  4. A.
    k cal/°C
    B.
    °C/k cal
    C.
    °C sec/k cal
    D.
    none of the above

  5. Assertion (A): In the given figure open loop transfer function =

    Reason (R): The ratio is called feed forward transfer function.

  6. 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

  7. Nichols chart consists of M and N locii in log magnitude versus phase diagram.

  8. A.
    True
    B.
    False

  9. If , initial and final values of i(t) are

  10. A.
    zero and 1
    B.
    zero and 10
    C.
    10 and zero
    D.
    70 and 80

  11. The gain margin of first and second order systems is infinite.

  12. A.
    True
    B.
    False

  13. One advantage of using polar plot is that it depicts the frequency response characteristics over the entire frequency.

  14. A.
    True
    B.
    False

  15. The force required to initiate motion between two contacting surfaces is called

  16. A.
    coulomb friction
    B.
    viscous friction
    C.
    static friction
    D.
    none of the above

  17. Assertion (A): Derivative control action cannot be used alone.

    Reason (R): Derivative control action is effective only during transient periods.

  18. 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

  19. The slope of log magnitude curve near the cut off frequency is called cut off rate.

  20. A.
    True
    B.
    False