A train is moving with a constant speed u along a circular track. A siren in its engine is emitting a sound of frequency v. If u = v/10, where v is the speed of sound, the apparent frequency of sound as heard by a passenger at the rear end of the train is
Refer to Fig.
The components of along the direction of the velocity of sound are and given . Thus, the source is receding from the observer with a speed and the observer is approaching the source with the same speed
Hence the correct chose is (d)