Basic Qualification · B-006 Feedlines and antenna systems · B-006-001-009
A transmission line is terminated by an impedance that differs significantly from the characteristic impedance of the line. What impedance will be measured at the input of the line?
- A An infinite impedance
- B A zero impedance
- C An impedance nearly equal to the characteristic impedance
- D A value of impedance influenced by line length
Correct answer: D — A value of impedance influenced by line length. From the official ISED question bank, verified word for word.
Why
When a transmission line ends with an impedance that does not match its own characteristic impedance, signals bounce back and forth inside the cable. 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.