The dB is defined as the ______ of two intensities.

The dB is defined as the ______ of two intensities.

• A. Difference
• B. Product
• C. Ratio
• D. Sun

Answer: (C)

Decibels express how many times larger one quantity is compared with another, using a logarithmic scale. For intensity, the dB value is defined as ten times the base-10 logarithm of the ratio of two intensities (I1/I0). This means a dB value communicates how many times brighter one signal is relative to another without using a simple subtraction. The logarithmic ratio makes it easy to compare very large or very small differences and, in systems, allows gains and attenuations to be added in dB rather than multiplied. This choice aligns with the concept of a ratio, not a difference or a product, and obviously not something unrelated. (If you were dealing with pressure instead of intensity, you’d use 20 log10(p1/p0) because intensity is proportional to pressure squared.)

Decibels express how many times larger one quantity is compared with another, using a logarithmic scale. For intensity, the dB value is defined as ten times the base-10 logarithm of the ratio of two intensities (I1/I0). This means a dB value communicates how many times brighter one signal is relative to another without using a simple subtraction. The logarithmic ratio makes it easy to compare very large or very small differences and, in systems, allows gains and attenuations to be added in dB rather than multiplied.

This choice aligns with the concept of a ratio, not a difference or a product, and obviously not something unrelated. (If you were dealing with pressure instead of intensity, you’d use 20 log10(p1/p0) because intensity is proportional to pressure squared.)