Z3D153 - 2016 Edit Code 3, Volume 1 Part 3

20 Questions | Total Attempts: 118

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Z3D153 Quizzes & Trivia

RF Transmissions Journeyman CDCs. Split up 20 questions at a time.


Questions and Answers
  • 1. 
    What are the three general categories used to produce modulation in radio frequency (RF) transmission today?
    • A. 

      Binary amplitude shift keying, frequency shift keying, and phase shift keying.

    • B. 

      Pulse amplitude, pulse width, and pulse position.

    • C. 

      Amplitude, frequency, and phase.

    • D. 

      Analog, digital and shift keying.

  • 2. 
    When the modulating signal and carrier signal are combined within a modulator, the output signal contains
    • A. 

      Modulating signal, upper sideband, and lower sideband.

    • B. 

      Carrier, upper sideband, and lower sideband.

    • C. 

      Upper sideband and modulating signal.

    • D. 

      Carrier and modulating signal.

  • 3. 
    What factor determines the spacing of the sidebands in an amplitude modulated signal?
    • A. 

      Amplitude of the modulating signal.

    • B. 

      Frequency of the modulating signal.

    • C. 

      Amplitude of the carrier signal.

    • D. 

      Frequency of the carrier signal.

  • 4. 
    The amount of effect or change that the intelligence has on the carrier in an amplitude modulated signal is expressed as the
    • A. 

      Percent of modulation.

    • B. 

      Modulation index.

    • C. 

      Bandwidth.

    • D. 

      Deviation.

  • 5. 
    Reducing modulation to less than 100 percent gives
    • A. 

      More total power.

    • B. 

      A reduction in carrier power.

    • C. 

      No reduction in carrier power.

    • D. 

      A reduction in carrier and sideband power.

  • 6. 
    The output of the oscillator in a frequency modulation (FM) modulator increases in frequency with each
    • A. 

      Positive half cycle of the carrier.

    • B. 

      Negative half cycle of the carrier.

    • C. 

      Positive half cycle of the modulating signal.

    • D. 

      Negative half cycle of the modulating signal.

  • 7. 
    A 5 kilohertz (kHz) modulating signal has enough peak voltage to cause a deviation of 15kHz. What is the modulation index?
    • A. 

      5.

    • B. 

      3.

    • C. 

      0.5.

    • D. 

      0.3.

  • 8. 
    What is the narrow frequency band between adjacent stations used to prevent frequency modulated sidebands from overlapping?
    • A. 

      Space.

    • B. 

      Guard band.

    • C. 

      Buffer zone.

    • D. 

      Prevention field.

  • 9. 
    What is the advantage of adding more phase shifts?
    • A. 

      Easier detection.

    • B. 

      Smaller bit error rate.

    • C. 

      Better signal-to-noise ratio.

    • D. 

      Higher data rates within a given bandwidth.

  • 10. 
    What is the first step in the pulse code modulation process?
    • A. 

      Discrete amplitudes are assigned to the sampling pulses.

    • B. 

      A binary code number is assigned to the sample.

    • C. 

      The quantizer limits the amplitude of the pulses.

    • D. 

      The analog signal is band limited.

  • 11. 
    Quantization in the pulse code modulation process is
    • A. 

      Converting a continuous time signal into a discrete time signal.

    • B. 

      Ensuring the input to the sampler never exceeds maximum frequency.

    • C. 

      Placing an infinite number of amplitude values to a finite number of values.

    • D. 

      Limiting the highest and lowest frequency encoded before it goes to the sampler.

  • 12. 
    In asynchronous transmissions, what bit is used by the receiving device to verify that the transmission was received correctly?
    • A. 

      Control.

    • B. 

      Parity.

    • C. 

      Start.

    • D. 

      Stop.

  • 13. 
    If an error should occur, what transmission is lost in an synchronous transmission?
    • A. 

      One character.

    • B. 

      Block of data.

    • C. 

      A parity bit.

    • D. 

      A stop bit.

  • 14. 
    The significance the amount of ones have in a data bit pattern when using vertical redundancy check (VRC) is that it determines
    • A. 

      Parity.

    • B. 

      Transmission rate.

    • C. 

      Whether transmission is synchronous or asynchronous.

    • D. 

      Whether transmission is in American Standard Code for Information Interchange (ASCII) format.

  • 15. 
    What two error detection methods, when used together, are 98 percent effective in detecting errors?
    • A. 

      Longitudinal redundancy check (LRC) and checksum.

    • B. 

      Checksum and cyclic redundancy check (CRC).

    • C. 

      Vertical redundancy check (VRC) and CRC.

    • D. 

      VRC and LRC.

  • 16. 
    When using forward error control as a method of error correction, where does error correction take place?
    • A. 

      Receiving end.

    • B. 

      In the oscillator.

    • C. 

      Transmitting end.

    • D. 

      In the primary buffers.

  • 17. 
    In telecommunications cable, the “tip” or “primary” wire color group order is
    • A. 

      White, blue, green, yellow, and violet.

    • B. 

      Blue, orange, green, brown, and slate.

    • C. 

      White, red, black, yellow, and violet.

    • D. 

      Blue, green, yellow, red, and orange.

  • 18. 
    Two types of network cables are
    • A. 

      Straight through and crossover.

    • B. 

      Straight through and flip/flop.

    • C. 

      High and low baud.

    • D. 

      “n” and “g”.

  • 19. 
    An optical transmitter is comprised of
    • A. 

      Positive intrinsic negative and avalanche photodiodes.

    • B. 

      Repeaters, regenerators, and optical amplifiers.

    • C. 

      A driver, optical source, and fiber optic pigtail.

    • D. 

      A light detector and output circuits.

  • 20. 
    What is the bandwidth of multimode step-index optical fiber cable?
    • A. 

      10 MHz – 100 MHz/km.

    • B. 

      100 MHz – 200 MHz/km.

    • C. 

      200 MHz – 1000 MHz/km.

    • D. 

      Up to 50 GHz/km.