Advanced Qualification · A-002 Advanced components and circuits · A-002-012-005
Les radioamateurs utilisent des cavités résonantes comme :
- Afiltre passe-haut au-dessus de 30 MHz
- Bfiltre passe-bande étroit aux fréquences VHF et supérieures
- Cfiltre à l'alimentation du secteur
- Dfiltre passe-bas sous 30 MHz
Correct answer: B — filtre passe-bande étroit aux fréquences VHF et supérieures. Question tirée de la banque officielle d'ISDE.
Why
Resonant cavities act like hollow metal boxes that naturally vibrate at one specific frequency, allowing only a very narrow slice of signals to pass while blocking others. The full explanation — and one for every question — is in Pro.
Practise this section
Advanced components and circuits is section A-002 of the Advanced exam: Advanced components and circuits: semiconductors, amplifier classes, oscillators, mixers, filters and digital logic.
Drill A-002 — free, no account