Technician exam question T3C08
Subelement T3, RADIO WAVE PROPAGATION· Group T3C
What causes tropospheric ducting?
- A.Discharges of lightning during electrical storms
- B.Sunspots and solar flares
- C.Updrafts from hurricanes and tornadoes
- D.Temperature inversions in the atmosphere (correct answer)
WhyTemperature inversions in the atmosphere cause tropospheric ducting. Tropospheric ducting forms when a layer of warm air sits on top of cooler air near the ground, a temperature inversion, creating a boundary that VHF/UHF signals can become trapped beneath and guided along for unusually long distances, answer D. Lightning (A), solar activity (B), and storm updrafts (C) are all real atmospheric or space-weather phenomena, but none of them create the specific temperature-layering structure that causes ducting.
Published 2026-08-28 · Last updated 2026-08-28 · Question text is verbatim from the 2026-2030 NCVEC Element 2 pool (public domain); the explanation above is original writing, see our methodology.
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