Intensity level of sound whose intensity is 10 -8 wm -2 is ….dB

SOLUTION

CONCEPT:

• Sound Intensity: It is also known as acoustic intensity.
• It is the power carried by sound waves per unit area in a direction perpendicular to that area.
• The sound intensity level is just a logarithmic expression of sound intensity relative to a reference intensity. Mathematically

\(L = 10log_{10}\frac{I}{I_0}\)

where L is the Level of the sound intensity, I is the intensity of the sound intensity, and I₀ is the reference intensity.

I₀ = 10^-12 w/m²

CALCULATION:

Given that I = 10^-8 w/m2

Intensity level of sound \(L = 10log_{10}\frac{I}{I_0}\)

\(L = 10log_{10}\frac{10^{-8}}{10^{-12}}\)

\(L = 10log_{10}{10^{4}}\)

\(L = 40log_{10}{10}\)

L = 40 dB

So the correct answer is option 3.