The quality of a musical sound depends on :

1. number of subsidiary notes
2. relative amplitudes
3. both (1) and (2)
4. none of the above

(a) Which of the following quantity determines the loudness of a sound wave?

(i) wavelength,

(ii) frequency, and

(iii) amplitude.

(b) How is loudness related to the quantity mentioned in the above part (a)

Two waves of the same pitch have amplitudes in the ratio 1 : 3. What will be the ratio of their (i) loudness and (ii) frequencies?

Name the unit in which the loudness of sound is measured?