A source of sound of frequency n is moving towards a stationary observer with a speed S. If the speed of sound in air is V and the frequency heard by the observer is n1, the value of n1/n is 

(1) (V + S)/V

(2) V/(V + S)

(3) (VS)/V

(4) V/(VS)

(4) By using n'=nvvvSn1n=VVS

Difficulty Level:

  • 9%
  • 24%
  • 18%
  • 50%