Basic Qualification · B-003 Station assembly, practice and safety · B-003-009-002
In a 3-element Yagi antenna, what is the longest radiating element?
- AThe director
- BThe driven element
- CThe reflector
- DThe boom
Correct answer: C — The reflector. From the official ISED question bank, verified word for word.
Why
In a three-element Yagi antenna, the reflector is the longest radiating element because its extra length makes it resonate at a slightly lower frequency, which helps bounce radio waves forward toward the shorter director. The full explanation — and one for every question — is in Pro.
Practise this section
Station assembly, practice and safety is section B-003 of the Basic exam: Building a station safely: power supplies, grounding, RF exposure, lightning, feedline routing, and what a transmitter, receiver and transceiver actually do.
Drill B-003 — free, no account