Question

If we reduce the amplitude of a sound wave to one-third, then the loudness becomes-

• A. 9 times
• B. 3 times
• C. 1/9 times
• D. 1/3 times.

Answer 1

The correct option is C

1/9 times

1. Loudness is directly proportional to the square of the amplitude of a sound wave-
2. $L\alpha A^2$; where L is Loudness and A is amplitude.
3. If amplitude becomes one-third means A/3 then-
4. Loudness becomes${(A/3)}^2$.
5. So, Loudness becomes L/9.
6. Final Answer- If we reduce the amplitude of a sound wave to one-third, then the loudness becomes 1/9 times.
7. Thus, the correct option is (C).