Basic Qualification · B-006 Feedlines and antenna systems · B-006-006-009
If an antenna is correctly matched to a transmission line, the length of the transmission line:
- Amust be a full wavelength long
- Bmust be an odd number of quarter-wavelengths
- Cmust be an even number of half-wavelengths
- Dwill have no effect on the matching
Correct answer: D — will have no effect on the matching. From the official ISED question bank, verified word for word.
Why
When an antenna is correctly matched to a transmission line, the impedance at the antenna end equals the line's characteristic impedance, meaning no signal reflects back. 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