JEE Main 2018PhysicsWaves and SoundHardMCQ

JEE Main 2018 — Waves and Sound Question with Solution

JEE Main 2018 (15 Apr)

Question

A tuning fork vibrates with frequency 256 Hz and gives one beat per second with the third normal mode of vibration of an open pipe. What is the length of the pipe? (speed of sound in air is 340 m s-1)

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Show full solutionCorrect option: B
Correct answer
B200 cm

Step-by-step explanation

Organ pipe will have frequency either 255 or  257 Hz. Using 255 Hz,
255= 3v2l,⇒l=3×3402×255 m⇒l=200 cm. Using 257 Hz,257= 3v2l'⇒l'=3×3402×257 m=198 cm.

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About this question

This is a previous-year question from JEE Main 2018, 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.