LESSON 3
PRACTICE EXERCISE
ANSWER KEY AND FEEDBACK
Item
Correct Answer and Feedback
1.
C.
Sky waves
Sky wave propagation allows transmitted signals to be reflected (bounced) off a
portion of the Earth's ionosphere and picked up at a receiver hundreds or even
thousands of miles away. (page 3-1, Introduction)
2.
B.
The intensity of the ultraviolet light waves
The rat at which ionization occurs in the ionosphere depends on the density of
atoms in the atmosphere and the intensity of the ultraviolet light waves. (page 3-
2, para la)
3.
A.
D
The D layer refracts low frequency signals, but high frequencies pass right
through it and are attenuated. (page 3-2, para c(l))
4.
D.
LF
Ionospheric reflection is more likely to occur at long wavelengths (low
frequencies). (page 3-4, para 1d(1))
5.
B.
1,500
The E region is used during the day for HF radio transmissions in ranges up to
about 1500 miles. (page 3-2, para 1c(2))
6.
C.
Degree of ionization present
The size of the skip distance depends on the frequency of the wave, the angle of
incidence, and the degree of ionization present. (page 3-5, para 1e(1))
7.
A.
D
The D layer refracts low frequency signals, but high frequencies pass right
through it and are attenuated. (page 3-2, para 1c(l))
SS0130
3-14
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