Basic Qualification · B-006 Feedlines and antenna systems · B-006-010-003
If you made a half-wavelength vertical antenna for 223 MHz, approximately how long would it be?
- A32 cm
- B105 cm
- C135 cm
- D67 cm
Correct answer: D — 67 cm. From the official ISED question bank, verified word for word.
Why
At 223 MHz, a full radio wave is about 134 centimetres long, so a half-wavelength antenna must be half that distance, which is roughly 67 cm. 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