Q 11-14-024NEETJEE MainMedium
A train sounding a whistle of $600$ Hz approaches and then passes a stationary listener at $30$ m/s. The change in frequency heard by the listener as the train passes is (speed of sound $= 330$ m/s)
Answer: (D) $110$ Hz
Approaching: $600 \times \dfrac{330}{300} = 660$ Hz. Receding: $600 \times \dfrac{330}{360} = 550$ Hz. Change $= 110$ Hz.
Solution by Sreeraj P, M.Sc Physics