Basic Qualification · B-007 Radio wave propagation · B-007-003-003
Quelle est la distance maximale, sur la surface de la Terre, que peut parcourir une onde radio réfléchie une seule fois par la couche ionosphérique E?
- A300 km
- B4 000 km
- C1 000 km
- D2 000 km
Correct answer: D — 2 000 km. Question tirée de la banque officielle d'ISDE.
Why
The E region of the ionosphere sits lower than the F region, so it reflects radio waves back to Earth at a shorter angle, typically allowing a single bounce to cover about 2000 km. 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