MCQ
Frequency of a sonometer wire is $n.$ Now its tension is increased $4$ times and its length is doubled then new frequency will be
  • A
    $n/2$
  • B
    $4n$
  • C
    $2n$
  • $n$

Answer

Correct option: D.
$n$
d
(d) $n \propto \frac{1}{l}\sqrt T $

==> $\frac{{n'}}{n} = \sqrt {\frac{{T'}}{T}} \times \frac{l}{{l'}} = \sqrt 4 \times \frac{1}{2} = 1$

==> $n' = n$

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