Medium MCQ +4 / -1 PYQ · JEE Mains 2020

A wire of length L and mass per unit length 6.0 × 10–3 kgm–1 is put under tension of 540 N. Two consecutive frequencies that it resonates at are : 420 Hz and 490 Hz. Then L in meters is :

  1. A 5.1 m
  2. B 2.1 m Correct answer
  3. C 1.1 m
  4. D 8.1 m

Solution

Fundamental frequency = 70 Hz. <br><br>70 = ${1 \over {2l}}\sqrt {{T \over \mu }}$ <br><br>$\Rightarrow$ $l$ = 2.14 m

About this question

Subject: Physics · Chapter: Waves · Topic: Wave Motion and Types

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