Basic Qualification · B-006 Feedlines and antenna systems · B-006-013-003
What is the approximate length of the driven element of a quad antenna designed for 21.4 MHz?
- A10.93 metres
- B3.57 metres
- C14.30 metres
- D7.01 metres
Correct answer: C — 14.30 metres. From the official ISED question bank, verified word for word.
Why
A quad antenna's driven element forms a square loop, so its total wire length must equal one full wavelength. The full explanation — and one for every question — is in Pro.
Practise this section
Feedlines and antenna systems is section B-006 of the Basic exam: Getting the signal out: antennas, feedlines, SWR, baluns, matching, and why antenna length depends on frequency.
Drill B-006 — free, no account