﻿ A train blowing its whistle moves with a constant velocity u away from the observer on the ground. The ratio of the actual frequency of the whistle to that measured by the observer is found to be 1.2. If the train is at rest and the observer moves away from it at the same velocity, the ratio would be given by : Kaysons Education

# A Train Blowing Its Whistle Moves With A Constant Velocity u away From The Observer On The Ground. The Ratio Of The Actual Frequency Of The Whistle To That Measured By The Observer Is Found To Be 1.2. If The Train Is At Rest And The Observer Moves Away From It At The Same Velocity, The Ratio Would Be Given By

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## Question

### Solution

Correct option is

1.25

If the train is going away from the observer, the apparent frequency is

It is observed that V = 1.2 V1. In the second case, the apparent frequency is

Now, from (i) we have  or u = 0.2 v or  Using this in (ii), we get

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