Basic Qualification · B-007 Radio wave propagation · B-007-003-010
La distance d'un saut d'une onde ionosphérique est d'autant plus longue que:
- Al'angle entre la direction du rayonnement et le sol est plus petit
- Bla polarisation est verticale
- Cl'ionosphère est plus fortement ionisée
- Dle signal émis est plus fort
Correct answer: A — l'angle entre la direction du rayonnement et le sol est plus petit. Question tirée de la banque officielle d'ISDE.
Why
When you aim a sky wave at a very low angle, nearly parallel to the ground, the radio signal travels a long distance before hitting the ionosphere and bouncing back down. 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