3d154 Vol 3 &4

179 Questions | Total Attempts: 395

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Air Force Quizzes & Trivia

URE questions from Vol 3 & 4


Questions and Answers
  • 1. 
    The low-density stream of charged particles emitted from the Sun is known as what?
    • A. 

      Solar wind.

    • B. 

      Solar radiation.

    • C. 

      Ultraviolet rays.

    • D. 

      Aurora borealis.

  • 2. 
    Earth’s atmosphere is broken down into how many layers?
    • A. 

      3

    • B. 

      4

    • C. 

      5

    • D. 

      6

  • 3. 
    What part of the atmosphere extends from Earth’s surface to heights of about 7.5 miles above Earth?
    • A. 

      Ionosphere.

    • B. 

      Mesosphere.

    • C. 

      Troposphere.

    • D. 

      Stratosphere.

  • 4. 
    Which layer of the atmosphere includes the ionosphere?
    • A. 

      Mesosphere.

    • B. 

      Troposphere

    • C. 

      Stratosphere.

    • D. 

      Thermosphere.

  • 5. 
    The presence or absence and height above Earth of the F1 and F2 ionospheric layers vary with the position of the
    • A. 

      Sun.

    • B. 

      Earth.

    • C. 

      Moon.

    • D. 

      Earth’s magnetic flux.

  • 6. 
    What ionospheric layer reflects HF signals during the daytime?
    • A. 

      D

    • B. 

      E

    • C. 

      F1

    • D. 

      F2

  • 7. 
    What regular ionospheric variation is attributed to Earth’s revolving around the Sun and the tilting of Earth’s axis during this rotation?
    • A. 

      Daily variations.

    • B. 

      Seasonal variations.

    • C. 

      27-day sunspot cycle.

    • D. 

      11-year sunspot cycle.

  • 8. 
    What irregular ionospheric variation can actually help HF communications by letting stations propagate on unusually high frequencies or allow sky wave propagation to close stations?
    • A. 

      Sporadic E.

    • B. 

      Solar flares.

    • C. 

      Ionospheric storms.

    • D. 

      Sudden ionospheric disturbances.

  • 9. 
    Which occurrence is not an irregular variation of the ionosphere?
    • A. 

      Diurnal.

    • B. 

      Solar flare.

    • C. 

      Sporadic E.

    • D. 

      Ionospheric storm.

  • 10. 
    What irregular ionospheric variation is caused by the Sun rotating on its axis?
    • A. 

      Daily variations.

    • B. 

      Seasonal variations.

    • C. 

      27-day sunspot cycle.

    • D. 

      11-year sunspot cycle.

  • 11. 
    What irregular ionospheric variation produces a burst of radiation across the electromagnetic spectrum and may last from minutes to hours in duration?
    • A. 

      Sporadic E.

    • B. 

      Solar flares.

    • C. 

      27-day sunspot cycle.

    • D. 

      11-year sunspot cycle.

  • 12. 
    What device do you use to determine the virtual height of any ionospheric layer?
    • A. 

      Multimeter.

    • B. 

      Ohmmeter.

    • C. 

      Horizontal radar.

    • D. 

      Ionospheric sounder.

  • 13. 
    F-layer critical frequencies generally fall in what frequency range?
    • A. 

      1 to 15 MHz.

    • B. 

      2 to 6 MHz.

    • C. 

      3 to 30 MHz.

    • D. 

      15 to 30 MHz.

  • 14. 
    What is the area of silence between the weakest ground wave reception and the point the sky wave first returns to Earth called?
    • A. 

      Skip zone.

    • B. 

      Diffraction.

    • C. 

      Skip distance.

    • D. 

      Skip difference.

  • 15. 
    What component of the ground wave travels directly from the transmit antenna to the receive antenna?
    • A. 

      Direct.

    • B. 

      Surface.

    • C. 

      Skip distance.

    • D. 

      Skip difference.

  • 16. 
    What wave propagation effect makes use of general weather phenomena and air turbulence to refract radio waves to the receiving station?
    • A. 

      Sky.

    • B. 

      Surface.

    • C. 

      Reflected.

    • D. 

      Tropospheric.

  • 17. 
    The area where the transmitter antenna and receiver antennas intersect and share common airspace in troposcatter propagation is known as
    • A. 

      Critical angle.

    • B. 

      Scatter volume.

    • C. 

      Critical zone.

    • D. 

      Scatter angle.

  • 18. 
    What is the most common piece of equipment for troposcatter communications in the Air Force today?
    • A. 

      AN/FRC–107.

    • B. 

      AN/GRC–206.

    • C. 

      AN/TPQ–43.

    • D. 

      AN/TRC–170.

  • 19. 
    Which data item is not found on a Spectrum XXI HF sky wave analysis output?
    • A. 

      Local time period.

    • B. 

      Transmit location.

    • C. 

      Universal time period.

    • D. 

      Type of radio being used.

  • 20. 
    Automated link establishment (ALE) equipment is comprised of
    • A. 

      Computer-controlled HF radios.

    • B. 

      Advanced Global Positioning System (GPS) landing systems.

    • C. 

      Land mobile radio (LMR) units that incorporate cellular phones.

    • D. 

      Military strategic and tactical relay (MILSTAR) satellite controller systems.

  • 21. 
    What do computer-controlled automated link establishment (ALE) radios use to allow them to handshake with other ALE radios in the network
    • A. 

      Formulas.

    • B. 

      Channels.

    • C. 

      Protocols.

    • D. 

      Distant station.

  • 22. 
    What is the first thing you look at when selecting an antenna for a HF circuit?
    • A. 

      Power capability.

    • B. 

      Type of equipment.

    • C. 

      Type of propagation.

    • D. 

      Authorized frequencies.

  • 23. 
    What is the worst type of antenna to use for sky wave circuits?
    • A. 

      Whip.

    • B. 

      Long-wire.

    • C. 

      Inverted V.

    • D. 

      Rotatable log periodic antenna (RLPA).

  • 24. 
    You can make a long-wire antenna directional by
    • A. 

      Switching propagation modes.

    • B. 

      Placing a balun on the antenna input.

    • C. 

      Decreasing the power output of the radio.

    • D. 

      Placing a terminating device at the distant station end of the antenna.

  • 25. 
    What type of antenna should be used for low frequency and short-distance HF circuits?
    • A. 

      Long-wire.

    • B. 

      Inverted-L.

    • C. 

      Inverted-V.

    • D. 

      Near vertical incidence sky wave (NVIS).

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