General exam question G9A10
Subelement G9, ANTENNAS AND FEED LINES· Group G9A
G9A10
What standing wave ratio results from connecting a 50-ohm feed line to a 10-ohm resistive load?
- A.2:1
- B.1:2
- C.1:5
- D.5:1 (correct answer)
WhyConnecting a 50-ohm feed line to a 10-ohm resistive load results in a 5:1 standing wave ratio. SWR from a resistive mismatch is the ratio of the larger impedance to the smaller, so connecting a 50-ohm line to a 10-ohm load gives 50 divided by 10, a 5:1 SWR, answer D. A, B, and C either invert the ratio or use the wrong pair of numbers, none matching this mismatch correctly.
Published 2026-08-28 · Last updated 2026-08-28 · Question text is verbatim from the 2023-2027 NCVEC Element 3 pool (public domain); the explanation above is original writing, see our methodology.
Related questions
- G9A01Which of the following factors determine the characteristic impedance of a parallel conductor feed line?
- G9A02What is the relationship between high standing wave ratio (SWR) and transmission line loss?
- G9A03What is the nominal characteristic impedance of “window line” transmission line?
- G9A04What causes reflected power at an antenna’s feed point?
- G9A05How does the attenuation of coaxial cable change with increasing frequency?