Question

When we change feeble sound to loud sound we increase its
A. Frequency
B. Amplitude
C. Velocity
D. Wavelength

Answer 1

Hint: The loudness of the sound is characterized by the energy of sound. A loud sound is heard till a greater distance whereas a feeble sound diminishes in a smaller distance and is not heard at far off points. Recall the factors that determine the loudness or intensity of sound.

Complete answer:
Frequency of sound is defined as the number of vibrations per second. It is just the inverse of time period. Its unit is Hertz. The amplitude is the maximum displacement of the wave from the mean position. Speed of sound is the distance travelled by sound per unit time.

Wavelength of sound is the distance between two adjacent crests or two adjacent troughs.
Amongst these, amplitude is the quantity which determines the loudness of a sound.
Loudness is directly proportional to the amplitude of sound. The larger the amplitude the louder the sound and the more energy the sound waves contain.Hence, when we change feeble sound to loud sound we increase its amplitude.

Hence option B is the correct answer.

Note:Students should know the characteristics of sound and then physical terms associated with sound. Also the relations between these quantities are important.Sound is a mechanical wave that is propagated through the medium due to the to and fro motion of the particles of the medium itself. The particles of the medium vibrate about their mean position only.