Basic Qualification · B-006 Feedlines and antenna systems · B-006-009-003
If a half-wave dipole is converted to a Yagi by adding a slightly shorter parasitic element, in what direction(s) does the radiation strength increase?
- A In both directions parallel to the elements
- B From the dipole towards the new element
- C From the new element towards the dipole
- D In both directions at right angles to the elements
Correct answer: B — From the dipole towards the new element. From the official ISED question bank, verified word for word.
Why
A parasitic element slightly shorter than the dipole is a director. 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.