Basic Qualification · B-007 Radio wave propagation · B-007-001-009
Quel type d'onde radio suit un trajet depuis l'émetteur jusqu'à l'ionosphère et revient vers la Terre?
- AL'onde directe
- BL'onde diffusée
- CL'onde plane
- DL'onde de ciel
Correct answer: D — L'onde de ciel. Question tirée de la banque officielle d'ISDE.
Why
A sky wave is the name for a radio signal that travels upward, bounces off the ionosphere (a layer of charged particles high in the atmosphere), and returns to Earth far from the transmitter. 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