Home / ECE / Network Analysis and Synthesis :: Section 20

ECE :: Network Analysis and Synthesis

  1. Which of the following is an I.S.I. symbol of cut-out power?


  2. If Fourier transform of f(t) is F(jω), then which pairs of time functions and Fourier transforms are matched

    1. f (t + 2) - ej F(jω)
    2. f (-0.5t) - 2F (-2jω)
    3. -
    Select the answer using the following codes

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

  4. In a power system, reactive power is necessary for

  5. A.
    power transmission
    B.
    stabilising the voltage level
    C.
    counteracting the effect of reactance in the transmission system
    D.
    none of the above

  6. A unit impulse voltage δ (t - b) is applied to an inductor with inductance L. The current through L is

  7. A.
    B.
    C.
    δ (t - b)
    D.

  8. A periodic voltage has following values for equal time intervals changing suddenly from one value to next, 0, 5, 10, 20, 50, 60, 50, 20, 10, 5, 0, -5, -10 etc. then rms value of the waveform is

  9. A.
    31 volt
    B.
    32 volt
    C.
    insufficient data
    D.
    none

  10. The impedance of a coil above self-resonant frequency is

  11. A.
    inductive
    B.
    capacitive
    C.
    resistive
    D.
    none

  12. Wire-wound resistors are unsuitable for use at high frequencies because they

  13. A.
    are likely to melt under excessive eddy current heat
    B.
    exhibit unwanted inductive and capacitive effects
    C.
    create more electrical noise
    D.
    consume more power

  14. In figure, the tree branches are bdf. The fundamental loops include

  15. A.
    abc, def, bdea
    B.
    cea, bdea, abc
    C.
    cdb, def, bfa
    D.
    abde, def, cdb

  16. A function Z(s) has zero at infinity if

  17. A.
    the degree of numerator and denominator are equal
    B.
    the numerator of Z(s) is one degree higher than denominator
    C.
    the denominator of Z(s) is one degree higher than numerator
    D.
    the degree of numerator and denominator are either equal or differ by one

  18. If f1 and f2 and half-power frequency and f0 be resonant frequency, the selectivity of R-L-C series circuit is given by

  19. A.
    (f2 - f1)/2f0
    B.
    (f2 - f1)/f0
    C.
    (f2 - f0)/(f1 - f0)
    D.
    (f2 - f1)/(f1 - f0)