Question

Loudness of sound increases with

• A. The amplitude of vibrating body
• B. The increase in surface area of vibrating body
• C. The decrease in frequency of vibrating body
• D. The increase in distance from the source of sound

Answer 1

Answer: (A), (B)

The increase in surface area of vibrating body

The explanation for the correct option(s):

A: The increase in the amplitude of the vibrating body:

1. Loudness is the property of sound that refers to how loud or soft a sound seems to a listener.
2. Loudness or intensity of sound is directly proportional to the square of the amplitude of the wave.
3. More the amplitude of the sound, the louder the sound and vice versa.

B: The increase in surface area of the vibrating body:

1. Loudness or intensity of the sound is directly proportional to the surface area of the vibrating body.
2. More the surface area of the vibrating body, the more will be the intensity of sound produced by it and vice versa.

The explanation for incorrect option(s):

C: The decrease in the frequency of the vibrating body

1. Loudness is independent of the frequency of sound and only the pitch of the sound depends on its frequency.

D: The increase in distance from the source of sound

1. Loudness of the sound decreases with an increase in distance from the source of the sound and vice versa.

Hence, options (A) and (B) are correct.