Basic Qualification · B-007 Radio wave propagation · B-007-002-002
Quel type de rayonnement solaire est principalement responsable de l'ionisation de la haute atmosphère?
- AL'infrarouge
- BL'ultraviolet
- CLes micro-ondes
- DLes particules ionisées
Correct answer: B — L'ultraviolet. Question tirée de la banque officielle d'ISDE.
Why
Ultraviolet radiation from the Sun carries enough energy to strip electrons from atoms in the upper atmosphere, creating the ionized layers that allow radio waves to bounce back to Earth. 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