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A source of sound S emitting waves of frequency 100 Hz and an observer O are located at some distance from each other. The source is moving with a speed of 19.4 m s - 1 at an angle of 60 o with the source observer line as shown in the figure. The observer is at rest. The apparent frequency observed by the observer (velocity of sound in air 330 m s - 1 ) is ​

Options

  1. A103 Hz
  2. B106   Hz
  3. C97   Hz
  4. D100   Hz

Correct answer

A. 103 Hz

Step-by-step solution

f = f 0 v - v 0 v - v s f = 100 v - 0 v - + 9.7 f = 100 v v 1 - 9.7 v f = 100 1 + 3.7 330 = 103 H z

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