Basic Qualification · B-006 Feedlines and antenna systems · B-006-001-003
The characteristic impedance of a 20-metre piece of transmission line is 52 ohms. What would the impedance be if 10 metres were cut off?
- A 104 ohms
- B 13 ohms
- C 52 ohms
- D 26 ohms
Correct answer: C — 52 ohms. From the official ISED question bank, verified word for word.
Why
Characteristic impedance is a fixed property of a transmission line determined by its physical construction, such as the spacing and size of the conductors, not by how long the cable is. The full explanation — and one for every question — is in Pro.
Practise this section
Getting the signal out: antennas, feedlines, SWR, baluns, matching, and why antenna length depends on frequency.