JEE Main 2019PhysicsWaves and SoundMediumMCQ

JEE Main 2019Waves and Sound Question with Solution

JEE Main 2019 (09 Apr Shift 2)

Question

Two cars A and B are moving away from each other in opposite directions. Both the cars are moving with speed of 20 m s-1 with respect to the ground. If an observer in car A detects a frequency 2000 Hz of the sound coming from car B, what is the natural frequency of the sound source in car B?
(speed of sound in air =340 m s-1 )

Choose an option

Show full solutionCorrect option: C
Correct answer
C2250 Hz

Step-by-step explanation

From Doppler effect: f'=VV0V±VSf0
2000=340-20340+20f0=320360f0
f0=98×2000=2250Hz

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About this question

This is a previous-year question from JEE Main 2019, 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.