2A251 Volume 5 UREs

100 Questions | Total Attempts: 85

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2A251 Quizzes & Trivia

Questions and Answers
  • 1. 
    If a radar echo returnes after 310 microseconds, how far away is the target?
    • A. 

      10 miles

    • B. 

      25 miles

    • C. 

      50 miles

    • D. 

      75 miles

  • 2. 
    In which radar system does the transmitter produce a signal that regularly changes over a known range of frequencies?
    • A. 

      Beacon

    • B. 

      Frequency-shift

    • C. 

      Pulse-modulation

    • D. 

      Frequency-modulation

  • 3. 
    In a pulse-modulation radar system, the transmitter does not interfere with the receiver. This is possible because the transmitter
    • A. 

      Is turned off after each pulse.

    • B. 

      Shifts the frequency of the pulse

    • C. 

      Transmits on a different frequency

    • D. 

      Uses a different antenna than the receiver

  • 4. 
    Which radar system is based on the Doppler principle?
    • A. 

      Beacon

    • B. 

      Frequency-shift

    • C. 

      Pulse-modulation

    • D. 

      Frequency-modulation

  • 5. 
    In a pulse-modulation radar system, a high pulse repetition frequency radar limits range by
    • A. 

      Using less power

    • B. 

      Using more power

    • C. 

      Shortening listening time

    • D. 

      Lengthening listening time

  • 6. 
    Which component in a pulse-modulation radar set supplies the voltages that operate the other radar components?
    • A. 

      Antenna

    • B. 

      Indicator

    • C. 

      Transmitter

    • D. 

      Power Supply

  • 7. 
    Which component in a pulse-modulation radar system controls the operation of the entire radar set?
    • A. 

      Antenna

    • B. 

      Indicator

    • C. 

      Transmitter

    • D. 

      Synchronizer

  • 8. 
    Where does the radar transmitter in a pulse-modulation radar system send a small amount of energy for use as a time reference?
    • A. 

      Antenna

    • B. 

      Receiver

    • C. 

      Indicator

    • D. 

      Power Supply

  • 9. 
    The minimum range of a pulse-modulation radar system is determined by the pulse
    • A. 

      Shape

    • B. 

      Duration

    • C. 

      Recurrence time

    • D. 

      Repetition frequency

  • 10. 
    As the pulse duration of a radar system increases, what will happen to the systems minimum and maximum range?
    • A. 

      Minimum range will increase, maximum range will increase

    • B. 

      Minimum range will increase, maximum range will decrease

    • C. 

      Minimum range will decrease, maximum range will decrease

    • D. 

      Minimum range will decrease, maximum range will increase

  • 11. 
    The maximum range of a pulse-modulation radar system primarily depends on
    • A. 

      Pulse shape

    • B. 

      Power output

    • C. 

      Pulse recurrence time

    • D. 

      Pulse repitition frequency

  • 12. 
    In a frequency-shift radar system, the Doppler principle makes it possible to instantaneously sense and measure
    • A. 

      Altitude and ground track

    • B. 

      Target elevation and speed

    • C. 

      Groundspeed and drift angle

    • D. 

      Magnetic heading and altitude

  • 13. 
    In a frequency-shift radar system, what is the relationship between a transmitter/receiver(T/R) and an aircraft when the received frequency is lower that the transmitted frequency?
    • A. 

      They are a constant distance away from each other

    • B. 

      The aircraft is not reflecting any of the radar pulses

    • C. 

      The aircraft is flying toward the T/R

    • D. 

      The aircraft is flying away from the T/R

  • 14. 
    If the operating frequency is 100m megahertz (MHZ) with a wavelength of 3 meters, then the frequency determining wall of the waveguide would be
    • A. 

      .9 meters

    • B. 

      1.5 meters

    • C. 

      2.1 meters

    • D. 

      2.7 meters

  • 15. 
    The function of a dummy load in search and weather radar is to
    • A. 

      Simulate a capacitive load

    • B. 

      Simulate a resistive load

    • C. 

      Prevent standing waves

    • D. 

      Simulate targets

  • 16. 
    What component is used to couple radio frequency energy between the waveguide and test equipment
    • A. 

      Feedhorn

    • B. 

      Duplexer

    • C. 

      Dummy Load

    • D. 

      Directional Coupler

  • 17. 
    What is triggered when the AS-653C Radar Antenna Reflector rotates through the aircraft lubber line?
    • A. 

      Bearing Circuit

    • B. 

      Tilt control circuit

    • C. 

      Stabilization circuit

    • D. 

      Heading marker circuit

  • 18. 
    Which component in the AN/APN-59 Radar System furnishes both pitch and roll drive signals to the antenna stabilization motors?
    • A. 

      AS-653C

    • B. 

      RT-289G

    • C. 

      AM-853B

    • D. 

      CN-221A

  • 19. 
    What component in the AN/APN-59 Radar System provides stabilized pitch and roll reference data for control of antenna orientation, despite changes in aircraft altitude?
    • A. 

      CN-221A

    • B. 

      RT-289G

    • C. 

      AM-853B

    • D. 

      C-1242A

  • 20. 
    What is the maximum height that the combined altitude radar altimeter subsystem computes aircraft altitude above ground level?
    • A. 

      5,000 feet

    • B. 

      25,000 feet

    • C. 

      35,000 feet

    • D. 

      50,000 feet

  • 21. 
    When power is applied to the combined altitude radar altimeter, what is shown on the digital display?
    • A. 

      All eights

    • B. 

      All dashes

    • C. 

      The word INIT

    • D. 

      The word TEST

  • 22. 
    What is/are the function(s) of the SET knob located on the combined altitude radar altimeter indicator?
    • A. 

      Used as an on/off control

    • B. 

      Used as an on/off control and to set the VALI indicator

    • C. 

      Used as an on/off control and as a test button to check the system

    • D. 

      Used as an on/off control, to set the VALI indicator, and as a test button to check the system

  • 23. 
    What is the maximum altitude that the analog pointer and dial of the combined altitude radar altimeter can display?
    • A. 

      5,000 feet

    • B. 

      10,000 feet

    • C. 

      25,000 feet

    • D. 

      50,000 feet

  • 24. 
    Which radar application is used to produce a pictorial map of the terrain?
    • A. 

      Ground mapping

    • B. 

      Terrain following

    • C. 

      Terrain avoidance

    • D. 

      Synthetic aperture radar

  • 25. 
    Which radar application is used primarily as an aid to navigation
    • A. 

      Search radar

    • B. 

      Ground mapping

    • C. 

      Terrain following

    • D. 

      Terrain avoidance

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