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A bat flies at steady speed of 4" m s"^(...

A bat flies at steady speed of `4" m s"^(-1)` emitting a sound of `f=90xx10^(3)`. Hz It is flying horizontally towards a vertical wall. The frequency of the reflected sound as detected by the bat will be
(Take velocity of sound in air as `330" m s"^(-1)`)

A

`92.1 xx 10^(3)` Hz

B

`89.1 xx 10^(3)` Hz

C

`88.1 xx 10^(3)` Hz

D

`87.1 xx 10^(3)` Hz

Text Solution

Verified by Experts

The correct Answer is:
A
the frequency of reflected sound as detected by the bat will be
`v. = ((v + mu_(0))/(v - u_(s)) ) ` v
` v. = ((350 + 5)/(330 - 4) ) xx 90 xx 10^(3)`
`v. = 92.1 xx 10^(3) `Hz.
So correct choice is a.
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Knowledge Check

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