Technician exam question T3A08
Subelement T3, RADIO WAVE PROPAGATION· Group T3A
What is a likely cause of irregular fading of signals propagated by the ionosphere?
- A.Frequency shift due to Faraday rotation
- B.Interference from thunderstorms
- C.Intermodulation distortion
- D.Random combining of signals arriving via different paths (correct answer)
WhyIrregular fading of signals propagated by the ionosphere is likely caused by the random combining of signals arriving via different paths. Ionospheric propagation rarely travels a single, clean path, signals reach the receiver via multiple slightly different routes through the ionosphere that combine randomly as conditions shift, producing the irregular rise and fall known as fading, answer D. Faraday rotation (A) affects polarization rather than causing fading in this irregular way, thunderstorm interference (B) is noise, not fading, and intermodulation (C) is a receiver-generated distortion product, not a propagation effect.
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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