An observer moves towards a stationary source of sound of frequency n. The apparent frequency heard by him is 2n. If the velocity of sound in air is 332 m/sec, then the velocity of the observer is [MP PET 1990]
n′=n(v+v0v)⇒=2n=n(v+v0v)⇒v+v0v=2
⇒v0=v=332 m/sec