JEE Main 2021PhysicsWaves and SoundEasyNumerical

JEE Main 2021Waves and Sound Question with Solution

JEE Main 2021 (27 Aug Shift 1)

Question

Two cars X and Y are approaching each other with velocities 36 km h-1 and 72 km h-1 respectively. The frequency of a whistle sound as emitted by a passenger in car X, heard by the passenger in car Y is 1320 Hz. If the velocity of sound in air is 340 ms-1, the actual frequency of the whistle sound produced is ________ Hz.

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Show full solutionCorrect answer: 1210
Correct answer
1210

Step-by-step explanation

f'=f0V+V0 V-VS

f0=1320340-10340+20=1320×3336=1210 Hz

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About this question

This is a previous-year question from JEE Main 2021, covering the Waves and Sound chapter of Physics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.