If the intensity level by 15 identical engines in a garage is 100 dB, what is the intensity level generated by each one of these engines?
A) 88 dB
B) 67 dB
C) 13 dB
D) 44 dB

Question

Quizplus · Accepted Answer

The intensity level in decibels (dB) can be calculated using the formula $L = 10 \log(I/I_0)$, where $I$ is the intensity of the sound and $I_0$ is the reference intensity. When the number of identical sound sources is increased, the total intensity is the sum of the individual intensities. For 15 identical engines producing a total of 100 dB, the intensity level of each engine can be found by first dividing the total intensity by 15 (since decibels are a logarithmic measure, we actually subtract 10 times the log of 15 from the total dB level). The calculation is as follows: $100 dB - 10 \log(15) = 100 dB - 11.76 dB = 88.24 dB$, which is approximately 88 dB.

If the Intensity Level by 15 Identical Engines in a Garage