Q. The intensity of sound gets reduced by 10% on passing through a slab. The reduction in intensity on passing through three consecutive slab is
A) 30%
B) 27.1%
C) 20%
D) 36%
Explanation
(b) Reduction in intensity after passing through first slab is $90/100$
Of I=0.9I
After second slab, intensity
=90% of (0.9I)
=81% of I
=0.81I
After third slab, intensity =90% of (0.81I)
=72.9% of I
∴ reduction in intensity =27.1%
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.