Technician exam question T5B09
Subelement T5, ELECTRICAL PRINCIPLES· Group T5B
Which decibel value most closely represents a power increase from 5 watts to 10 watts?
- A.2 dB
- B.3 dB (correct answer)
- C.5 dB
- D.10 dB
WhyA power increase from 5 watts to 10 watts is most closely represented by 3 dB. Doubling power corresponds to a 3 dB increase (ten times the base-10 logarithm of the power ratio, and ten times log of 2 works out to about 3), and going from 5 watts to 10 watts is exactly a doubling, so 3 dB is the closest value, answer B. The other choices don't match the doubling-equals-3-dB relationship worth memorizing for the exam.
Published 2026-08-28 · Last updated 2026-08-28 · Question text is verbatim from the 2026-2030 NCVEC Element 2 pool (public domain); the explanation above is original writing, see our methodology.