Wave Mechanics Question 1104
Question: A point source emits sound equally in all directions in a non-absorbing medium. Two points $ P $ and $ Q $ are at distances of $ 2m $ and $ 3m $ respectively from the source. The ratio of the intensities of the waves at $ P $ and $ Q $ is
[CBSE PMT 2005]
Options:
A) 9 : 4
B) 2 : 3
C) 3 : 2
D) 4 : 9
Show Answer
Answer:
Correct Answer: A
Solution:
Intensity $ \propto \frac{1}{{{\text{(Distance)}}^{\text{2}}}} $
Therefore $ \frac{I _{1}}{I _{2}}={{( \frac{d _{2}}{d _{1}} )}^{2}}={{( \frac{3}{2} )}^{2}}=\frac{9}{4} $ .
BETA
