The intensity at a distance of 6.0 m from a source that is radiating equally in all directions is 6.0 × 10-10 W/m2. What is the intensity level in dB? The threshold of human hearing is 1.0 × 10-12
W/m2.
A) 23 dB
B) 28 dB
C) 18 dB
D) 32 dB

Question

Quizplus · Accepted Answer

The intensity level in decibels (dB) can be calculated using the formula: $ \text{Level (dB)} = 10 \log_{10} \left( \frac{I}{I_0} \right) $, where $I$ is the intensity of the sound and $I_0$ is the reference intensity, which is the threshold of human hearing (1.0 × 10^-12 W/m^2 in this case). Plugging in the given values: $ \text{Level} = 10 \log_{10} \left( \frac{6.0 \times 10^{-10}}{1.0 \times 10^{-12}} \right) = 10 \log_{10} (600) \approx 28 $ dB.

The Intensity at a Distance of 6