By how many decibels does the intensity level of a sound increase when you triple the intensity of a source of sound?

a) 3.0 db
b) 4.8 db
c) 12 db
d) 9.5 db
e) 6.0 db

To solve this problem we will apply the concepts related to Sound Intensity. From the expression of decibels, the intensity of the sound defined as acoustic power transferred by a sound wave per unit of normal area to the direction of propagation. Mathematically it can be expressed as,

Where,

I = Intensity of sound

I_0 = hearing threshold

If we take these values for the two intensity levels we would have to

The total difference between the two intensity would then give us that

Since the statement intensity 1 is 3 times greater than intensity 2. Therefore

Therefore the correct option is B.

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