Question

Decibel is the unit of physical quantity used for :

• A. The speed of light
• B. The intensity of heat
• C. The intensity of sound
• D. The frequency of radiowaves

Answer 1

The correct option is C The intensity of sound

Answer is C.
The intensity or loudness of a sound depends upon the extent to which the sounding body vibrates, i.e., the amplitude of vibration. A sound is louder as the amplitude of vibration is greater, and the intensity decreases as the distance from the source increases. Loudness or intensity of sound is measured in units called decibels.