Question

If the amplitude of the sound is made 3 times its initial value, then its loudness will become _______________ times its initial value.

• A. 9
• B. 4
• C. 16
• D. 25

Answer 1

The correct option is A 9

If the amplitude of the sound is made 3 times its initial value, then its loudness will become nine times its initial value.
Loudness depends on the square of the amplitude of the wave.
That is, $Loudness\propto {\left(Amplitude\right)}^2$.
Thus, when amplitude of the wave is tripled, the loudness increases nine times.