ELEMENT 2 - TECHNICIAN CLASS


Question Pool

SUBELEMENT T3 -- RADIO-WAVE PROPAGATION [3 Exam Questions -- 3 Groups] T3A Line of sight; reflection of VHF/UHF signals T3A01 (B)
How are VHF signals propagated within the range of the visible horizon? A. By sky wave B. By line of sight C. By plane wave
D. By geometric refraction T3A02 (A)
When a signal travels in a straight line from one antenna to another, what is this called? A. Line-of-sight propagation B. Straight line propagation
C. Knife-edge diffraction
D. Tunnel ducting T3A03 (B)
How do VHF and UHF radio waves usually travel from a transmitting antenna to a receiving antenna? A. They bend through the ionosphere B. They go in a straight line C. They wander in any direction
D. They move in a circle going either east or west from the transmitter T3A04 (C)
What type of propagation usually occurs from one hand-held VHF transceiver to another nearby? A. Tunnel propagation
B. Sky-wave propagation C. Line-of-sight propagation D. Auroral propagation T3A05 (A)
What causes the ionosphere to form? A. Solar radiation ionizing the outer atmosphere B. Temperature changes ionizing the outer atmosphere
C. Lightning ionizing the outer atmosphere
D. Release of fluorocarbons into the atmosphere T3A06 (C)
What type of solar radiation is most responsible for ionization in the outer atmosphere? A. Thermal
B. Non-ionized particle C. Ultraviolet D. Microwave T3A07 (C)
Which two daytime ionospheric regions combine into one region at night? A. E and F1
B. D and E C. F1 and F2 D. E1 and E2 T3A08 (C)
Which ionospheric region becomes one region at night, but separates into two separate regions during the day? A. D
B. E C. F D. All of these choices T3A09 (B)
Ultraviolet solar radiation is most responsible for ionization in what part of the atmosphere? A. Inner B. Outer C. All of these choices
D. None of these choices T3A10 (A)
What part of our atmosphere is formed by solar radiation ionizing the outer atmosphere A. Ionosphere B. Troposphere
C. Ecosphere
D. Stratosphere T3A11 (C)
What can happen to VHF or UHF signals going towards a metal-framed building? A. They will go around the building
B. They can be bent by the ionosphere C. They can be easily reflected by the building D. They are sometimes scattered in the ecosphere T3B Tropospheric ducting or bending; amateur satellite and EME operations T3B01 (C)
Ducting occurs in which region of the atmosphere? A. F2
B. Ecosphere C. Troposphere D. Stratosphere T3B02 (A)
What effect does tropospheric bending have on 2-meter radio waves? A. It lets you contact stations farther away B. It causes them to travel shorter distances
C. It garbles the signal
D. It reverses the sideband of the signal T3B03 (D)
What causes tropospheric ducting of radio waves? A. A very low pressure area
B. An aurora to the north
C. Lightning between the transmitting and receiving stations D. A temperature inversion T3B04 (B)
What causes VHF radio waves to be propagated several hundred miles over oceans? A. A polar air mass B. A widespread temperature inversion C. An overcast of cirriform clouds
D. A high-pressure zone T3B05 (A)
In which of the following frequency ranges does tropospheric ducting most often occur? A. UHF B. MF
C. HF
D. VLF T3B06 (A)
What weather condition may cause tropospheric ducting? A. A stable high-pressure system B. An unstable low-pressure system
C. A series of low-pressure waves
D. Periods of heavy rainfall T3B07 (C)
How does the signal loss for a given path through the troposphere vary with frequency? A. There is no relationship
B. The path loss decreases as the frequency increases C. The path loss increases as the frequency increases D. There is no path loss at all T3B08 (B)
Why are high-gain antennas normally used for EME (moonbounce) communications? A. To reduce the scattering of the reflected signal as it returns to Earth B. To overcome the extreme path losses of this mode C. To reduce the effects of polarization changes in the received signal
D. To overcome the high levels of solar noise at the receiver T3B09 (D)
Which of the following antenna systems would be the best choice for an EME (moonbounce) station? A. A single dipole antenna
B. An isotropic antenna
C. A ground-plane antenna D. A high-gain array of Yagi antennas T3B10 (B)
When is it necessary to use a higher transmitter power level when conducting satellite communications? A. When the satellite is at its perigee B. When the satellite is low to the horizon C. When the satellite is fully illuminated by the sun
D. When the satellite is near directly overhead T3B11 (C)
Which of the following conditions must be met before two stations can conduct real-time communications through a satellite? A. Both stations must use circularly polarized antennas
B. The satellite must be illuminated by the sun during the communications C. The satellite must be in view of both stations simultaneously D. Both stations must use high-gain antenna systems T3C Ionospheric propagation, causes and variation; maximum usable frequency; Sporadic-E propagation; ground wave, HF propagation characteristics; sunspots and the sunspot cycle T3C01 (D)
Which region of the ionosphere is mainly responsible for absorbing MF/HF radio signals during the daytime? A. The F2 region
B. The F1 region
C. The E region D. The D region T3C02 (C)
If you are receiving a weak and distorted signal from a distant station on a frequency close to the maximum usable frequency, what type of propagation is probably occurring? A. Ducting
B. Line-of-sight C. Scatter D. Ground-wave T3C03 (A)
In relation to sky-wave propagation, what does the term "maximum usable frequency" (MUF) mean? A. The highest frequency signal that will reach its intended destination B. The lowest frequency signal that will reach its intended destination
C. The highest frequency signal that is most absorbed by the ionosphere
D. The lowest frequency signal that is most absorbed by the ionosphere T3C04 (D)
When a signal travels along the surface of the Earth, what is this called? A. Sky-wave propagation
B. Knife-edge diffraction
C. E-region propagation D. Ground-wave propagation T3C05 (A)
When a signal is returned to Earth by the ionosphere, what is this called? A. Sky-wave propagation B. Earth-Moon-Earth propagation
C. Ground-wave propagation
D. Tropospheric propagation T3C06 (C)
What is a skip zone? A. An area covered by ground-wave propagation
B. An area covered by sky-wave propagation C. An area that is too far away for ground-wave propagation, but too close for sky-wave propagation D. An area that is too far away for ground-wave or sky-wave propagation T3C07 (B)
Which ionospheric region is closest to the Earth? A. The A region B. The D region C. The E region
D. The F region T3C08 (D)
Which region of the ionosphere is mainly responsible for long-distance sky-wave radio communications? A. D region
B. E region
C. F1 region D. F2 region T3C09 (B)
Which of the ionospheric regions may split into two regions only during the daytime? A. Troposphere B. F C. Electrostatic
D. D T3C10 (A)
How does the number of sunspots relate to the amount of ionization in the ionosphere? A. The more sunspots there are, the greater the ionization B. The more sunspots there are, the less the ionization
C. Unless there are sunspots, the ionization is zero
D. Sunspots do not affect the ionosphere T3C11 (C)
How long is an average sunspot cycle? A. 2 years
B. 5 years C. 11 years D. 17 years

END OF SUB-ELEMENT T3