Basic Qualification · B-006 Feedlines and antenna systems · B-006-009-004
If a half-wave dipole is converted to a Yagi by adding a slightly longer element, in what direction(s) does the radiation strength increase?
- AIn both directions at right angles to the elements
- BIn both directions parallel to the elements
- CFrom the new element towards the dipole
- DFrom the dipole towards the new element
Correct answer: C — From the new element towards the dipole. From the official ISED question bank, verified word for word.
Why
Adding a slightly longer element behind the driven dipole creates a reflector that bounces radio waves forward, concentrating the signal from the new element toward the original dipole. The full explanation — and one for every question — is in Pro.
Practise this section
Feedlines and antenna systems is section B-006 of the Basic exam: Getting the signal out: antennas, feedlines, SWR, baluns, matching, and why antenna length depends on frequency.
Drill B-006 — free, no account