Wave Mechanics Question 68
Question: The minimum distance of reflector surface from the source for listening the echo of sound is
[CPMT 1997; RPMT 1999; KCET 2000]
Options:
A) 28 m
B) 18 m
C) 19 m
D) 16.5 m
Show Answer
Answer:
Correct Answer: D
Solution:
$ 2d=v\times t $ , where $ v= $ velocity of sound = 332 $ m/s $ t = Persistence of hearing = $ \frac{1}{10}\sec $ .
Therefore $ d=\frac{v\times t}{2}=\frac{332\times \frac{1}{10}}{2}=16.5 $
$ m $
BETA
