Extra exam question E9C04
Subelement E9, ANTENNAS AND TRANSMISSION LINES· Group E9C
What happens to the radiation pattern of an unterminated long wire antenna as the wire length is increased?
- A.Fewer lobes form with the major lobes increasing closer to broadside to the wire
- B.Additional lobes form with major lobes increasingly aligned with the axis of the antenna (correct answer)
- C.The elevation angle increases, and the front-to-rear ratio decreases
- D.The elevation angle increases, while the front-to-rear ratio is unaffected
WhyAs an unterminated long wire antenna's length increases, additional lobes form with the major lobes increasingly aligned with the axis of the antenna. As an unterminated long wire antenna's length increases, additional radiation lobes form, and the major lobes increasingly align closer to the wire's own axis rather than broadside to it, a well-known long-wire antenna characteristic, answer B. Longer wires don't produce fewer lobes with major lobes moving toward broadside, that's the opposite of what actually happens as wire length grows.
Published 2026-08-28 · Last updated 2026-08-28 · Question text is verbatim from the 2024-2028 NCVEC Element 4 pool (public domain); the explanation above is original writing, see our methodology.
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