Basic Qualification · B-006 Feedlines and antenna systems · B-006-002-006
What causes a transmission line to be unbalanced?
- A The conductors are twisted together
- B One conductor has a poor connection the antenna
- C The conductors have deteriorated insulation
- D One conductor is connected to ground
Correct answer: D — One conductor is connected to ground. From the official ISED question bank, verified word for word.
Why
A transmission line becomes unbalanced when one of its two conductors is tied to ground, creating an asymmetry where the currents flowing in each wire are no longer equal and opposite. 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.