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A siren emitting a sound of frequency moves away from an observer towards a cliff at a speed of . Then, the frequency of sound that the observer hears in the echo reflected from the cliff is: (Take velocity of sound in air )

  1. A
  2. B
  3. C
  4. D

Solution & Step-by-step Explanation

The cliff acts as a stationary observer receiving sound from a source moving towards it.Frequency received by cliff ():

The cliff then reflects this frequency. The observer is stationary, so the frequency heard in the echo is the same frequency that reached the cliff.

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A siren emitting a sound of frequency moves away from an observer towards a cliff at a speed of . Then, the frequency of sound that the observer hears in the echo reflected from the cliff is: (Take velocity of sound in air )
A
B
C
D

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