Basic Qualification · B-007 Radio wave propagation · B-007-005-008
Toutes les fréquences de communications du spectre subissent à des degrés divers l'influence:
- Ades aurores boréales
- Bdes pluies de météores
- Cdu Soleil
- Dde l'ionosphère
Correct answer: C — du Soleil. Question tirée de la banque officielle d'ISDE.
Why
The sun drives nearly every change in radio wave behaviour because its radiation creates and alters the ionosphere, the layer of charged particles that reflects signals. The full explanation — and one for every question — is in Pro.
Practise this section
Radio wave propagation is section B-007 of the Basic exam: How signals travel: the ionosphere and its layers, skip, ground wave, sporadic E, and which bands work when.
Drill B-007 — free, no account