JEE Main 2019PhysicsWaves and SoundEasyMCQ

JEE Main 2019 — Waves and Sound Question with Solution

JEE Main 2019 (09 Apr Shift 2)

Question

A string 2.0 m long and fixed at its ends is driven by a 240 Hz vibrator. The string vibrates in its third harmonic mode. The speed of the wave and its fundamental frequency is

Choose an option

Show full solutionCorrect option: B
Correct answer
B320  m s-1,  80  Hz

Step-by-step explanation

For a string fixed at both the ends,
f=n2Lv
For third harmonic, 240=32(2)v
⇒v=240×43
=320  m s-1
Fundamental frequency f0=12Lv
=14×320 = 80 Hz

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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.