AvdyneAeroservice:.Element #3B 40-Questions

Element #3B....Good luck!...and remember you will be asked 3 questions from this pool.

(E3B1) What is a selective fading effect?
1. A fading effect caused by small changes in beam heading at the receiving station.
2. A fading effect caused by phase differences between radio wave components of the same transmission, as experienced at the receiving station.
3. A fading effect caused by large changes in the height of the ionosphere, as experienced at the receiving station.
4. A fading effect caused by time differences between the receiving and transmitting stations.
(E3B2) What is the propagation effect called when phase differences between radio wave components of the same transmission are experienced at the recovery station?
1. Faraday rotation.
2. Diversity reception.
3. Selective fading.
4. Phase shift.
(E3B3) What is the major cause of selective fading?
1. Small changes in beam heading at the receiving station.
2. Large changes in the height of the ionosphere, as experienced at the receiving station.
3. Time differences between the receiving and transmitting stations.
4. Phase differences between radio wave components of the same transmission, as experienced at the receiving station.
(E3B4) Which emission modes suffer the most from selective fading?
1. CW and SSB.
2. FM and double sideband AM.
3. SSB and image.
4. SSTV and CW.
(E3B5) How does the bandwidth of the transmitted signal affect selective fading?
1. It is more pronounced at wide bandwidths.
2. It is more pronounced at narrow bandwidths.
3. It is equally pronounced at both narrow and wide bandwidths.
4. The receiver bandwidth determines the selective fading
  effect.
(E3B6) What phenomenon causes the radio-path horizon distance to exceed the geometric horizon?
1. E-layer skip.
2. D-layer skip.
3. Auroral skip.
4. Radio waves may be bent.
(E3B7) How much farther does the radio-path horizon distance exceed the geometric horizon?
1. By approximately 15% of the distance.
2. By approximately twice the distance.
3. By approximately one-half the distance.
4. By approximately four times the distance.
(E3B8) What propagation condition is usually indicated when a VHF signal is received from a station over 500 miles away?
1. D-layer absorption.
2. Faraday rotation.
3. Tropospheric ducting.
4. Moonbounce.
(E3B9) What happens to a radio wave as it travels in space and collides with other particles?
1. Kinetic energy is given up by the radio wave.
2. Kinetic energy is gained by the radio wave.
3. Aurora is created.
4. Nothing happens since radio waves have no physical substance.
(E3B10) When the earth's atmosphere is struck by a meteor, a cylindrical region of free electrons is formed at what layer of the ionosphere?
1. The Fl layer.
2. The E layer.
3. The F2 layer.
4. The D layer.
(E3B11) What is transequatorial propagation?
1. Propagation between two points at approximately the same distance north and south of the magnetic equator.
2. Propagation between two points on the magnetic equator.
3. Propagation between two continents by way of ducts along the magnetic equator.
4. Propagation between any two stations at the same latitude.
(E3B12) What is the maximum range for signals using transequatorial propagation?
1. About 1,000 miles.
2. About 2,500 miles.
3. About 5,000 miles.
4. About 7,500 miles.
(E3B13) What is the best time of day for transequatorial propagation?
1. Morning.
2. Noon.
3. Afternoon or early evening.
4. Transequatorial propagation only works at night.
(E3B14) What is knife-edge diffraction?
1. Allows normally line-of-sight signals to bend around sharp edges, mountain ridges, buildings and other obstructions.
2. Arcing in sharp bends of conductors.
3. Phase angle image rejection.
4. Line-of-sight signals causing distortion to other signals.
(E3B15) The bending of radio waves passing over the top of a mountain range that disperses a weak portion of the signal behind the mountain is:
1. Eddy-current phase effect.
2. Knife-edge diffraction.
3. Shadowing.
4. Mirror refraction effect.
(E3B16) Knife-edge diffraction:
1. Is the bending of UHF frequency radio waves around a building, mountain or obstruction.
2. Causes the velocity of wave propagation to be different from original wave.
3. Is the bending of UHF frequency radio waves around a building, mountain or obstruction and causes the velocity of wave propagation to be different from original wave.
4. Attenuates UHF signals.
(E3B17) If the elapsed time for a radar echo is 62 microseconds what is the distance in nautical miles to the object?
1. 5 nautical miles.
2. 87 nautical miles.
3. 37 nautical miles.
4. 11.5 nautical miles.
(E3B18) What is the wavelength of a signal at 500 MHz?
1. 0.062cm.
2. 6 meters.
3. 60cm.
4. 60 meters.
(E3B19) The radar range in nautical miles to an object can be found by measuring the elapsed time during a radar pulse and dividing this quantity by:
1. 0.87 seconds.
2. 1.15 microseconds.
3. 12.36 microseconds.
4. 1.73 microseconds.
(E3B20) The band of frequencies least susceptible to atmospheric noise and interference is:
1. 30-300 kHz.
2. 300 - 3000 kHz.
3. 3-30 MHz.
4. 300-3000 MHz.
(E3B21) What is the relationship in degrees of the electrostatic and electromagnetic fields of an antenna?
1. 0 degrees.
2. 45 degrees.
3. 90 degrees.
4. 180 degrees.
(E3B22) For a space wave transmission, the radio horizon distance of a transmitting antenna with a height of 100 meters is approximately:
1. 10km.
2. 40km.
3. 100 km.
4. 400km.
(E3B23) For a space wave transmission, the radio horizon distance of a receiving antenna with a height of 64 meters is approximately:
1. 8 km.
2. 32 km.
3. 64km.
4. 256km.
(E3B24) If a transmitting antenna is 100 meters high and a separate receiving antenna is 64 meters high, what is the maximum space wave communication distance possible between them?
1. 18km.
2. 72 km.
3. 164km.
4. 656km.
(E3B25) A receiver is located 64 km from a space wave transmitting antenna that is 100 meters high. Find the required height of the receiving antenna.
1. 36 meters high.
2. 64 meters high.
3. 100 meters high.
4. 182.25 meters high.
(E3B26) Which of the following is not one of the natural ways a radio wave may travel from transmitter to receiver?
1. Ground wave.
2. Micro wave.
3. Sky wave.
4. Space wave.
E3B27 Which of the following terrain types permits a ground waveto travel the farthest?
1. Salt water.
2. Fresh water.
3. Sandy.
4. Rocky.
(E3B28) Which of the following frequency bands is best suited for ground wave propagation?
1. 30 kHz to 300 kHz.
2. 300 kHz to 3 MHz.
3. 3 MHz to 30 MHz.
4. 30 MHz to 300 MHz.
(E3B29) Which of the following frequency bands is best suited for sky wave propagation?
1. 30 kHz to 300 kHz.
2. 3 MHz to 30 MHz.
3. 30 MHz to 300 MHz.
4. 3 GHz to 30 GHz.
(E3B30) Which of the following layers of the Ionosphere has no effect on sky wave propagation during the hours of darkness?
1. D.
2. E.
3. F.
4. None of these.
(E3B31) Which of the following least affects refraction of sky waves?
1. Frequency of the radio wave.
2. Density of the ionized layer.
3. Angle at which the radio wave enters the ionosphere
4. Geographical variations.
(E3B32) The area that lies between the outer limit of the ground wave range and the inner edge of energy returned from the Ionosphere is called :
1. The critical angle
2. The skip zone.
3. The skip distance.
4. The shadow.
(E3B33) Skip Distance can be maximized by using the __ radiation angle possible and the __ frequency that will be refracted at that angle.
1. Lowest, lowest.
2. Lowest, highest.
3. Highest, lowest.
4. Highest, highest.
(E3B34) To obtain the most reliable sky wave propagation the should be used.
1. Lowest useable frequency (LUF).
2. Maximum useable frequency (MUF).
3. Optimum useable frequency (OUF).
4. Critical frequency.
(E3B35) Tropospheric scatter is a method of sky wave propagation for which of the following frequency bands?
1. 300 kHz to 3 MHz.
2. 3 MHz to 30 MHz.
3. 30 MHz to 300 MHz.
4. 300 MHz to 3 GHz.
(E3B36) Which of the following methods are used for diversity reception to overcome the effects of tropospheric scattering of a sky wave?
1. Frequency diversity.
2. Phase diversity.
3. Amplitude diversity.
4. Critical diversity.
(E3B37) Which of the following will not significantly reduce the effects of fading?
1. Use an antenna with a good front to back ratio.
2. Use an antenna with a sharp frontal lobe.
3. Use an antenna with a minimum number of spurious side and back lobes.
4. Use an antenna with good omni directional pattern.
(E3B38) Which of the following terms is not used to define ionospheric variations?
1. Seasonal variations.
2. Geographical variations.
3. Cyclical variations.
4. Tropospheric scatter variations.
(E3B39) The polarization of a radio wave :
1. Is perpendicular to the electrostatic field of the antenna.
2. Is the same direction as the electrostatic field of the antenna.
3. Is the same direction as the magnetic field of the antenna.
4. Is perpendicular to both the electrostatic and magnetic fields of the antenna
(E3B40) The direction of propagation of a radio wave is __ to the electrostatic field of the antenna and __ to the magnetic field of the antenna.
1. Parallel, parallel
2. Parallel, perpendicular
3. Perpendicular, parallel
4. Perpendicular, perpendicular
(E3B41) Most AM broadcasts employ __ polarization while most FM broadcasts employ __ polarization of the radio wave.
1. Vertical, vertical
2. Vertical, horizontal
3. Horizontal, vertical
4. Horizontal, horizontal
(E3B42) Ducts often form over:
1. Dry and arid deserts
2. Cold arctic regions
3. Highly industrialized regions