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ECE :: Communication Systems

  1. Which of the following statement regarding the advantages of the phase discriminator over the slope detector is false?

  2. A.
    Better linearity
    B.
    Fewer tuned circuits
    C.
    Much easier alignment
    D.
    Greater limiting

  3. The highest modulating frequency typically used in AM systems is

  4. A.
    1 kHz
    B.
    5 kHz
    C.
    20 kHz
    D.
    50 kHz

  5. The line of sight communication requires the transmit and receive antennas to face each other. If the transmit antenna is vertically polarized, for best reception to the receive antenna should be

  6. A.
    horizontally polarized
    B.
    vertically polarized
    C.
    at 45° within respect to horizontal polarization
    D.
    at 45° with respect to vertical polarization

  7. The bandwidth of FM for Commercial Purpose is

  8. A.
    88 - 108 MHz
    B.
    85 - 110 MHz
    C.
    90 - 110 MHz
    D.
    infinite Range

  9. In home tape recorders the tape width is 2 inches.

  10. A.
    True
    B.
    False

  11. If e = 10 sin(108 t + 3 sin 104 t) then carrier frequency is

  12. A.
    0.159 MHz
    B.
    1.59 MHz
    C.
    15.9 MHz
    D.
    159 MHz

  13. Thermal noise is independent of

  14. A.
    temperature
    B.
    bandwidth
    C.
    centre frequency
    D.
    Boltzmann constant

  15. The decorative lighting works on the principle of

  16. A.
    periodic switching on and off
    B.
    special inverter
    C.
    rectifier
    D.
    motor

  17. In an oscillator crystal, the parallel resonant frequency is

  18. A.
    equal to
    B.
    higher than
    C.
    less than
    D.
    series resonant frequency

  19. The maximum range of a radar is proportional to

  20. A.
    square root of peak transmitted pulse power
    B.
    fourth root of peak transmitted pulse power
    C.
    peak transmitted pulse power
    D.
    none of the above