Wave Mechanics Question 1095
Question: The intensity of sound wave while passing through an elastic medium falls down by 10% as it covers one metre distance through the medium. If the initial intensity of the sound wave was 100 decibels, its value after it has passed through 3 metre thickness of the medium will be
[CPMT 1988]
Options:
A) 70 decibel
B) 72.9 decibel
C) 81 decibel
D) 60 decibel
Show Answer
Answer:
Correct Answer: B
Solution:
After passing the 3 meter intensity is given by $ I _{3}=\frac{90}{100}\times \frac{90}{100}\times \frac{90}{100}\times I=72.9%\ \text{of }I $ So, the intensity is 72.9 decibel.
BETA
