Basic Qualification · B-006 Feedlines and antenna systems · B-006-011-005
What is one effect of increasing the boom length and adding directors to a Yagi antenna?
- A Gain increases
- B Front-to-back ratio increases
- C Beamwidth increases
- D Power handling capability increases
Correct answer: A — Gain increases. From the official ISED question bank, verified word for word.
Why
Making a Yagi antenna longer by adding more directors focuses the radio signal into a tighter beam, which makes the signal stronger in that specific direction; this concentration of energy is called gain. 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.