Assertion (A): When we start filling an empty pitcher with water, the pitch of the sound produced goes on decreasing.

Reason (R): The pitch of sound increases with increase in frequency.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true and R is not the correct explanation of A.
3. assertion is false but reason is true.
4. assertion is true but reason is false.

(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?