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Subelement B-007

B-007

Section B-007-002

Section B-007-002

What causes the ionosphere to form?

  • Release of fluorocarbons into the atmosphere
  • Temperature changes ionizing the outer atmosphere
  • Lightning ionizing the outer atmosphere
  • Correct Answer
    Solar radiation ionizing the outer atmosphere

Ultraviolet (UV) radiation and particles emanating from the Sun break down molecules in the ionosphere to form charged ions.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

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What type of solar radiation is most responsible for ionization in the outer atmosphere?

  • Ionized particles
  • Infrared
  • Correct Answer
    Ultraviolet
  • Microwave

Ultraviolet (UV) radiation and particles emanating from the Sun break down molecules in the ionosphere to form charged ions.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

Which ionospheric region is closest to the Earth?

  • The F region
  • The A region
  • The E region
  • Correct Answer
    The D region

Above the troposphere and stratosphere, the regions of the ionosphere are: D, E, F1 and F2 (from lowest to highest).

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

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Which region of the ionosphere is the least useful for long-distance radio-wave propagation?

  • The E region
  • The F2 region
  • The F1 region
  • Correct Answer
    The D region

The D layer, lowest of the regions, is fairly dense. Once ionized during daylight hours, it ABSORBS lower frequencies ( i.e., 160 m and 80 m ).

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

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Which region of the ionosphere separates into two sub-regions in the daytime?

  • The G region
  • The D region
  • The E region
  • Correct Answer
    The F region

Key word: SUB-REGIONS. The F1 and F2 sub-regions present during the day combine at night to form the F region. D and E are two distinct regions of their own.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

When is the ionosphere most ionized?

  • Dusk
  • Correct Answer
    Midday
  • Dawn
  • Midnight

Key word: MOST. At midday, with the Sun shining directly at the ionosphere, ionization is most intense. As the Sun sets and throughout the night, ions recombine (how quickly depending on the density of a given layer) so that ionization is minimum right before dawn (sunrise).

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

When is ionization at a minimum in the ionosphere?

  • Just after dusk
  • Shortly before midnight
  • Just after noon
  • Correct Answer
    Shortly before dawn

Key word: LEAST. At midday, with the Sun shining directly at the ionosphere, ionization is most intense. As the Sun sets and throughout the night, ions recombine (how quickly depending on the density of a given layer) so that ionization is minimum right before dawn (sunrise).

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

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Why is the F2 region mainly responsible for the longest distance radio-wave propagation?

  • Correct Answer
    Because it is the highest ionospheric region
  • Because it does not absorb radio waves as much as other ionospheric regions
  • Because it exists only at night
  • Because it is the lowest ionospheric region

Above the troposphere and stratosphere, the regions of the ionosphere are: D, E, F1 and F2 (from lowest to highest).

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

What is the main reason the 160-metre and 80-metre bands tend to be useful only for short-distance communications during daylight hours?

  • Because of E region ionization
  • Because of E region absorption
  • Because of signal scattering
  • Correct Answer
    Because of D region absorption

The D region, lowest of the regions, is fairly dense. Once ionized during daylight hours, it ABSORBS lower frequencies ( i.e., 160 m and 80 m ).

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

During the day, what two sub-regions appear in the ionosphere?

  • Correct Answer
    F1 and F2
  • B1 and B2
  • D1 and D2
  • E1 and E2

The F1 and F2 sub-regions present during the day combine at night to form the F region. The other designations simply do not exist.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

What is the position of the E region in the ionosphere?

  • Above the F region
  • Correct Answer
    Below the F region
  • Above the C region
  • Below the D region

From the Earth up and above the troposphere and stratosphere, the regions of the ionosphere are: D, E, F1 and F2.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

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