The engine of a train moving with speed | Sound Wave

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JEE MAIN 2023

08-04-23 S1

Question

The engine of a train moving with speed $10 \mathrm{~ms}^{-1}$ towards a platform sounds a whistle at frequency 400 Hz . The frequency heard by a passenger inside the train is (neglect air speed. Speed of sound in air $330 \mathrm{~ms}^{-1}$ )

Select the correct option:

A

200 Hz

B

400 Hz

C

412 Hz

D

388 Hz

✓ Correct! Well done.

✗ Incorrect. Try again or view the solution.

Solution

The relative velocity of a passenger with source of sound (engine) is 0. So there will be no doppler’s effect. So frequency heard is 400 Hz.

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