Basic Qualification · B-006 Feedlines and antenna systems · B-006-004-009
If the length of a coaxial transmission line is increased from 20 metres to 40 metres, how would this affect the line loss?
- A It would be increased by 10%
- B It would be increased by 20%
- C It would be increased by 100%
- D It would be increased by 50%
Correct answer: C — It would be increased by 100%. From the official ISED question bank, verified word for word.
Why
Doubling the length of a coaxial cable from 20 to 40 metres doubles the total resistance and friction the signal faces, meaning the loss grows by exactly 100%. 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.