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ECE :: Communication Systems

  1. Which of the following are the types of FM Detectors
  2. A.
    Quadrature Detector
    B.
    Phase-Locked Loop (PLL) detector
    C.
    Foster-Seely Discriminator
    D.
    All the above

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  3. In _______ the sample values of the analog waveform are used to determine the width of the pulse signal
  4. A.
    PPM
    B.
    PWM
    C.
    PTM
    D.
    All the above

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  5. In _________ the analog sample values determine the position of a narrow pulse Relative to the clocking time
  6. A.
    PPM
    B.
    PWM
    C.
    PTM
    D.
    All the above

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  7. It is possible to obtain PPM from PWM by using a ________multivibrator circuit
  8. A.
    Astable
    B.
    Bistable
    C.
    Monostable
    D.
    None of these

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  9. The Modulation index of an AM Wave is changed from 0 to 1. The transmitted power is _________
  10. A.
    Unchanged
    B.
    Decreased by 50 %
    C.
    Doubled
    D.
    Increased by 50 %

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  11. The Modulation index of an AM Wave is changed from 0 to 1. The transmitted power is _________
  12. A.
    Unchanged
    B.
    Decreased by 50 %
    C.
    Doubled
    D.
    Increased by 50 %

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  13. In Amplitude modulation, the modulation envelope has a peak value which is double the unmodulated carrier value. What is the value of modulation index?
  14. A.
    25%
    B.
    50%
    C.
    75%
    D.
    100%

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  15. Time division multiplexing is used in _______
  16. A.
    Analog circuit
    B.
    Digital circuit
    C.
    Modulation circuit
    D.
    Multiplier circuit

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  17. The modulator stage in a radio transmitter is normally
  18. A.
    Class A
    B.
    Class B
    C.
    Class AB
    D.
    Class C

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  19. Power in an FM signal is dependent on __________
  20. A.
    The amplitude of the carrier
    B.
    The frequency of the carrier
    C.
    Both amplitude & frequency of a carrier
    D.
    None of these

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