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Waves and Sound — JEE physics STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 ScienceJEE physicsWaves and Sound1 Mark
MCQ
A string in musical instrument is $50 \mathrm{~cm}$ long and its fundamental frequency is $800 \mathrm{~Hz}$. If a frequency of $1000 \mathrm{~Hz}$ is to be produced, then required length of string is
  • A
    $62.5 \mathrm{~cm}$
  • B
    $50 \mathrm{~cm}$
  • ✓
    $40 \mathrm{~cm}$
  • D
    $37.5 \mathrm{~cm}$
✓

Answer

Correct option: C.
$40 \mathrm{~cm}$
(c) $n_1 l_1=n_2 l_2 \Rightarrow 800 \times 50=1000 \times l_2 \Rightarrow l_2=40 \mathrm{~cm}$

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