Extra exam question E8B05
Subelement E8, SIGNALS AND EMISSIONS· Group E8B
What 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?
- A.6
- B.0.167
- C.0.6
- D.1.67 (correct answer)
WhyAn FM phone signal with a maximum frequency swing of plus or minus 5 kHz and a highest modulation frequency of 3 kHz has a deviation ratio of about 1.67. Deviation ratio equals the maximum frequency deviation divided by the highest modulating frequency: 5 kHz divided by 3 kHz works out to approximately 1.67, answer D. The other figures come from inverting that ratio or otherwise miscalculating it.
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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