Which statement is true about decibel notation?

Which statement is true about decibel notation?

• A. It uses a linear scale.
• B. It uses a logarithmic scale.
• C. It uses a quadratic scale.
• D. It measures frequency.

Answer: (B)

Decibel notation uses a logarithmic scale to express ratios of quantities such as power or amplitude relative to a reference level. This is useful because levels in acoustics and electronics cover vast ranges, and our perception of loudness is roughly logarithmic, so the dB scale compresses those ranges into manageable numbers. In practice, power ratios are expressed as 10 log10(P2/P1), while amplitude or voltage ratios use 20 log10(V2/V1). That means small, multiplicative changes in the physical quantity show up as consistent, additive steps on the dB scale. For example, doubling the power corresponds to about +3 dB, while doubling the amplitude corresponds to about +6 dB. A tenfold increase in power is +10 dB. Decibels are a relative measure to a reference level (they’re not an absolute unit on their own), and you’ll often see them paired with a reference like dB SPL for sound pressure. They do not measure frequency.

Decibel notation uses a logarithmic scale to express ratios of quantities such as power or amplitude relative to a reference level. This is useful because levels in acoustics and electronics cover vast ranges, and our perception of loudness is roughly logarithmic, so the dB scale compresses those ranges into manageable numbers.

In practice, power ratios are expressed as 10 log10(P2/P1), while amplitude or voltage ratios use 20 log10(V2/V1). That means small, multiplicative changes in the physical quantity show up as consistent, additive steps on the dB scale. For example, doubling the power corresponds to about +3 dB, while doubling the amplitude corresponds to about +6 dB. A tenfold increase in power is +10 dB. Decibels are a relative measure to a reference level (they’re not an absolute unit on their own), and you’ll often see them paired with a reference like dB SPL for sound pressure. They do not measure frequency.