Extra exam question E9F01
Subelement E9, ANTENNAS AND TRANSMISSION LINES· Group E9F
What is the velocity factor of a transmission line?
- A.The ratio of its characteristic impedance to its termination impedance
- B.The ratio of its termination impedance to its characteristic impedance
- C.The velocity of a wave in the transmission line multiplied by the velocity of light in a vacuum
- D.The velocity of a wave in the transmission line divided by the velocity of light in a vacuum (correct answer)
WhyA transmission line's velocity factor is the velocity of a wave in the line divided by the velocity of light in a vacuum. A transmission line's velocity factor is the ratio of the actual speed a wave travels through that line to the speed of light in a vacuum, expressed as a decimal less than 1 since signals always travel slower in a real transmission line than in free space, answer D. It isn't an impedance ratio between characteristic and termination impedance, and it isn't a product of line velocity and the speed of light, velocity factor is specifically that speed ratio.
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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