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A whistle of frequency 500 Hz tied to th...

A whistle of frequency 500 Hz tied to the end of a string of length 1.2 m revolves at 400 rev / min . A listener standing some distance away in the plane of rotation of whistle hears frequencies in the range (speed of sound = 340 m / s )

A

436 to 586

B

426 to 574

C

426 to 584

D

436 to 674

Text Solution

Verified by Experts

The correct Answer is:
A
Speed of whistle -
`v_(s)=romega=1.2xx2pixx(400)/(60)=50m//s`
`f_(max)=f((v)/(v-v_(s)))=500((340)/(340-50))=586Hz`
`f_(min)=f((v)/(v+v_(s)))=500((340)/(340+50))=436Hz`
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