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A train moves towards a stationary observer with speed 34 m/s. The train sounds a whistle and its frequency registered by the observer is `f_(1)`. If the speed of train is reduced to 17 m/s, the frequency registered is `f_(2)`. If speed fo sound is 340 m/s, then the ratio `f_(1)//f_(2)` is :

A

`20/19`

B

`18/17`

C

`19/18`

D

`21/20`

Text Solution

Verified by Experts

The correct Answer is:
C
`f_1=((340)/(340-34))f`
`f_2=((340)/(340-17))fimplies f_1/(f_2) =((340-17)/(340-34))=19/18`
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