FCCライセンス General 6月 29 2024 SUBELEMENT G3A SUBELEMENT G3A G3A – Sunspots and solar radiation; geomagnetic field and stability indices 1 / 14 G3A01How does a higher sunspot number affect HF propagation? A. Higher sunspot numbers generally indicate a greater probability of good propagation at higher frequencies B. Lower sunspot numbers generally indicate greater probability of sporadic E propagation C. A zero sunspot number indicates that radio propagation is not possible on any band D. A zero sunspot number indicates undisturbed conditions 2 / 14 G3A02What effect does a sudden ionospheric disturbance have on the daytime ionospheric propagation? A. It enhances propagation on all HF frequencies B. It disrupts signals on lower frequencies more than those on higher frequencies C. It disrupts communications via satellite more than direct communications D. None, because only areas on the night side of the Earth are affected 3 / 14 G3A03Approximately how long does it take the increased ultraviolet and X-ray radiation from a solar flare to affect radio propagation on Earth? A. 28 days B. 1 to 2 hours C. 8 minutes D. 20 to 40 hours 4 / 14 G3A04Which of the following are the least reliable bands for long-distance communications during periods of low solar activity? A. 80 meters and 160 meters B. 60 meters and 40 meters C. 30 meters and 20 meters D. 15 meters, 12 meters, and 10 meters 5 / 14 G3A05What is the solar flux index? A. A measure of the highest frequency that is useful for ionospheric propagation between two points on Earth B. A count of sunspots that is adjusted for solar emissions C. Another name for the American sunspot number D. A measure of solar radiation with a wavelength of 10.7 centimeters 6 / 14 G3A06What is a geomagnetic storm? A. A sudden drop in the solar flux index B. A thunderstorm that affects radio propagation C. Ripples in the geomagnetic force D. A temporary disturbance in Earth’s geomagnetic field 7 / 14 G3A07At what point in the solar cycle does the 20-meter band usually support worldwide propagation during daylight hours? A. At the summer solstice B. Only at the maximum point C. Only at the minimum point D. At any point 8 / 14 G3A08How can a geomagnetic storm affect HF propagation? A. Improve high-latitude HF propagation B. Degrade ground wave propagation C. Improve ground wave propagation D. Degrade high-latitude HF propagation 9 / 14 G3A09How can high geomagnetic activity benefit radio communications? A. Creates auroras that can reflect VHF signals B. Increases signal strength for HF signals passing through the polar regions C. Improve HF long path propagation D. Reduce long delayed echoes 10 / 14 G3A10What causes HF propagation conditions to vary periodically in a 26- to 28-day cycle? A. Long term oscillations in the upper atmosphere B. Cyclic variation in Earth’s radiation belts C. Rotation of the Sun’s surface layers around its axis D. The position of the Moon in its orbit 11 / 14 G3A11How long does it take a coronal mass ejection to affect radio propagation on Earth? A. 28 days B. 14 days C. 4 to 8 minutes D. 15 hours to several days 12 / 14 G3A12What does the K-index measure? A. The relative position of sunspots on the surface of the Sun B. The short-term stability of Earth’s geomagnetic field C. The short-term stability of the Sun’s magnetic field D. The solar radio flux at Boulder, Colorado 13 / 14 G3A13What does the A-index measure? A. The relative position of sunspots on the surface of the Sun B. The amount of polarization of the Sun’s electric field C. The long-term stability of Earth’s geomagnetic field D. The solar radio flux at Boulder, Colorado 14 / 14 G3A14How is long distance radio communication usually affected by the charged particles that reach Earth from solar coronal holes? A. HF communication is improved B. HF communication is disturbed C. VHF/UHF ducting is improved D. VHF/UHF ducting is disturbed Your score isThe average score is 0% 0% Restart quiz Ed 0 コメント
