Extra exam question E8B09
Subelement E8, SIGNALS AND EMISSIONS· Group E8B
What is deviation ratio?
- A.The ratio of the audio modulating frequency to the center carrier frequency
- B.The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency (correct answer)
- C.The ratio of the carrier center frequency to the audio modulating frequency
- D.The ratio of the highest audio modulating frequency to the average audio modulating frequency
WhyDeviation ratio is the ratio of the maximum carrier frequency deviation to the highest audio modulating frequency. Deviation ratio is defined as the ratio of the maximum carrier frequency deviation to the highest audio modulating frequency used, a fixed figure that (unlike modulation index, which varies with the actual modulating tone in use at any given moment) describes a system's worst-case design parameters, answer B. It isn't a ratio involving the carrier's center frequency at all, and it isn't a ratio between different modulating frequencies, deviation ratio specifically relates peak deviation to peak modulating frequency.
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.
Related questions
- E8B01What is the modulation index of an FM signal?
- E8B02How does the modulation index of a phase-modulated emission vary with RF carrier frequency?
- E8B03What is the modulation index of an FM phone signal having a maximum frequency deviation of 3000 Hz either side of the carrier frequency if the highest modulating frequency is 1000 Hz?
- E8B04What is the modulation index of an FM phone signal having a maximum carrier deviation of plus or minus 6 kHz if the highest modulating frequency is 2 kHz?
- E8B05What is the deviation ratio of an FM phone signal having a maximum frequency swing of plus or minus 5 kHz if the highest modulation frequency is 3 kHz?