Basic Qualification · B-007 Radio wave propagation · B-007-006-008
Que se passe-t-il quotidiennement lorsque le rayonnement UV solaire augmente?
- ALe niveau de bruit atmosphérique diminue
- BLa propagation par onde de sol diminue
- CLes conditions météorologiques dans l'ionosphère changent
- DLa fréquence maximale utilisable augmente
Correct answer: D — La fréquence maximale utilisable augmente. Question tirée de la banque officielle d'ISDE.
Why
When solar ultraviolet radiation increases, it ionizes the upper atmosphere more strongly, creating denser layers of charged particles that can reflect higher radio frequencies 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