Extra exam question E9A09
Subelement E9, ANTENNAS AND TRANSMISSION LINES· Group E9A
What is antenna efficiency?
- A.Radiation resistance divided by transmission resistance
- B.Radiation resistance divided by total resistance (correct answer)
- C.Total resistance divided by radiation resistance
- D.Effective radiated power divided by transmitter output
WhyAntenna efficiency is radiation resistance divided by total resistance. Antenna efficiency is defined as radiation resistance divided by the antenna's total resistance (radiation resistance plus loss resistance), the fraction of input power that actually gets radiated rather than dissipated as heat in the antenna and ground system, answer B. It isn't total resistance divided by radiation resistance (that inverts the ratio), and it isn't effective radiated power divided by transmitter output, that conflates antenna efficiency with the combined effect of gain and system losses.
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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