E3 Questions
36 questions in this subelement. Click any question ID for more details.
Answer: B
What characterizes libration fading of an EME signal?
AA slow change in the pitch of the CW signal
BA fluttery, irregular fading
CA gradual loss of signal as the sun rises
DThe returning echo is several hertz lower in frequency than the transmitted signal
Answer: A
When scheduling EME contacts, which of these conditions will generally result in the least path loss?
AWhen the Moon is at perigee
BWhen the Moon is full
CWhen the Moon is at apogee
DWhen the MUF is above 30 MHz
Answer: D
In what direction does an electromagnetic wave travel?
AIt depends on the phase angle of the magnetic field
BIt travels parallel to the electric and magnetic fields
CIt depends on the phase angle of the electric field
DIt travels at a right angle to the electric and magnetic fields
Answer: C
How are the component fields of an electromagnetic wave oriented?
AThey are parallel
BThey are tangential
CThey are at right angles
DThey are 90 degrees out of phase
Answer: B
What should be done to continue a long-distance contact when the MUF for that path decreases due to darkness?
ASwitch to a higher frequency HF band
BSwitch to a lower frequency HF band
CChange to an antenna with a higher takeoff angle
DChange to an antenna with greater beam width
Answer: C
Atmospheric ducts capable of propagating microwave signals often form over what geographic feature?
AMountain ranges
BStratocumulus clouds
CLarge bodies of water
DNimbus clouds
Answer: A
When a meteor strikes the Earth’s atmosphere, a linear ionized region is formed at what region of the ionosphere?
AThe E region
BThe F1 region
CThe F2 region
DThe D region
Answer: C
Which of the following frequency ranges is most suited for meteor-scatter communications?
A1.8 MHz - 1.9 MHz
B10 MHz - 14 MHz
C28 MHz - 148 MHz
D220 MHz - 450 MHz
Answer: D
What determines the speed of electromagnetic waves through a medium?
AResistance and reactance
BEvanescence
CBirefringence
DThe index of refraction
Answer: B
What is a typical range for tropospheric duct propagation of microwave signals?
A10 miles to 50 miles
B100 miles to 300 miles
C1,200 miles
D2,500 miles
Answer: C
What is most likely to result in auroral propagation?
AMeteor showers
BQuiet geomagnetic conditions
CSevere geomagnetic storms
DExtreme low-pressure areas in polar regions
Answer: B
What are circularly polarized electromagnetic waves?
AWaves with an electric field bent into a circular shape
BWaves with rotating electric and magnetic fields
CWaves that circle Earth
DWaves produced by a loop antenna
Answer: C
What is the approximate maximum range for signals using transequatorial propagation?
A1,000 miles
B2,500 miles
C5,000 miles
D7,500 miles
Answer: C
At what time of day is transequatorial propagation most likely to occur?
AMorning
BNoon
CAfternoon or early evening
DLate at night
Answer: B
What are “extraordinary” and “ordinary” waves?
AExtraordinary waves exhibit rare long-skip propagation, compared to ordinary waves, which travel shorter distances
BIndependently propagating, elliptically polarized waves created in the ionosphere
CLong-path and short-path waves
DRefracted rays and reflected waves
Answer: D
Which of the following paths is most likely to support long-distance propagation on 160 meters?
AA path entirely in sunlight
BPaths at high latitudes
CA direct north-south path
DA path entirely in darkness
Answer: B
On which of the following amateur bands is long-path propagation most frequent?
A160 meters and 80 meters
B40 meters and 20 meters
C10 meters and 6 meters
D6 meters and 2 meters
Answer: C
What effect does lowering a signal’s transmitted elevation angle have on ionospheric HF skip propagation?
AFaraday rotation becomes stronger
BThe MUF decreases
CThe distance covered by each hop increases
DThe critical frequency increases
Answer: C
How does the maximum range of ground-wave propagation change when the signal frequency is increased?
AIt stays the same
BIt increases
CIt decreases
DIt peaks at roughly 8 MHz
Answer: A
At what time of year is sporadic-E propagation most likely to occur?
AAround the solstices, especially the summer solstice
BAround the solstices, especially the winter solstice
CAround the equinoxes, especially the spring equinox
DAround the equinoxes, especially the fall equinox
Answer: A
What is the effect of chordal-hop propagation?
AThe signal experiences less loss compared to multi-hop propagation, which uses Earth as a reflector
BThe MUF for chordal-hop propagation is much lower than for normal skip propagation
CAtmospheric noise is reduced in the direction of chordal-hop propagation
DSignals travel faster along ionospheric chords
Answer: D
At what time of day is sporadic-E propagation most likely to occur?
ABetween midnight and sunrise
BBetween sunset and midnight
CBetween sunset and sunrise
DBetween sunrise and sunset
Answer: B
What is chordal-hop propagation?
APropagation away from the great circle bearing between stations
BSuccessive ionospheric refractions without an intermediate reflection from the ground
CPropagation across the geomagnetic equator
DSignals reflected back toward the transmitting station
Answer: A
What type of polarization is supported by ground-wave propagation?
AVertical
BHorizontal
CCircular
DElliptical
Answer: A
What is indicated by a rising A-index or K-index?
AIncreasing disturbance of the geomagnetic field
BDecreasing disturbance of the geomagnetic field
CHigher levels of solar UV radiation
DAn increase in the critical frequency
Answer: B
Which of the following signal paths is most likely to experience high levels of absorption when the A- index or K-index is elevated?
ATransequatorial
BThrough the auroral oval
CSporadic-E
DNVIS
Answer: C
What does the value of Bz (B sub z) represent?
AGeomagnetic field stability
BCritical frequency for vertical transmissions
CNorth-south strength of the interplanetary magnetic field
DDuration of long-delayed echoes
Answer: A
What orientation of Bz (B sub z) increases the likelihood that charged particles from the Sun will cause disturbed conditions?
ASouthward
BNorthward
CEastward
DWestward
Answer: A
How does the VHF/UHF radio horizon compare to the geographic horizon?
AIt is approximately 15 percent farther
BIt is approximately 20 percent nearer
CIt is approximately 50 percent farther
DThey are approximately the same
Answer: D
Which of the following indicates the greatest solar flare intensity?
AClass A
BClass Z
CClass M
DClass X
Answer: D
Which of the following is the space-weather term for an extreme geomagnetic storm?
AB9
BX5
CM9
DG5
Answer: D
What type of data is reported by amateur radio propagation reporting networks?
ASolar flux
BElectric field intensity
CMagnetic declination
DDigital-mode and CW signals
Answer: B
What does the 304A solar parameter measure?
AThe ratio of X-ray flux to radio flux, correlated to sunspot number
BUV emissions at 304 angstroms, correlated to the solar flux index
CThe solar wind velocity at an angle of 304 degrees from the solar equator, correlated to geomagnetic storms
DThe solar emission at 304 GHz, correlated to X-ray flare levels
Answer: C
What does VOACAP software model?
AAC voltage and impedance
BVHF radio propagation
CHF propagation
DAC current and impedance
Answer: B
Which of the following is indicated by a sudden rise in radio background noise across a large portion of the HF spectrum?
AA temperature inversion has occurred
BA coronal mass ejection impact or a solar flare has occurred
CTransequatorial propagation on 6 meters is likely
DLong-path propagation on the higher HF bands is likely