Q. A sound absorber attenuates the sound level by 20 dB. The intensity decreases by a factor of
A) 100
B) 1000
C) 10000
D) 10
Explanation
(a) It is known that when loudness decreases by$10dB$, intensity of sound decreases by a factor $10$.therefore, when loudness decreases by$20\ dB$, $ie$,$2 \times 10\ dB$, the intensity of sound would decreases by a factor of $10^{2}$,ie 100.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.