14.Waves and Sound
hard

A wire having a linear mass density $9.0 \times 10^{-4} \;{kg} / {m}$ is stretched between two rigid supports with a tension of $900\; {N}$. The wire resonates at a frequency of $500\;{Hz}$. The next higher frequency at which the same wire resonates is $550\; {Hz}$. The length of the wire is $...... {m}$

A

$50$

B

$100$

C

$10$

D

$2$

(JEE MAIN-2021)

Solution

$\mu=9.0 \times 10^{-4}\, \frac{{kg}}{{m}}$

${T}=900\, {N}$

${V}=\sqrt{\frac{{T}}{\mu}}=\sqrt{\frac{900}{9 \times 10^{-4}}}=1000 \,{m} / {s}$

${f}_{1}=500 \,{Hz}$

${f}=550$

$\frac{{nV}}{2 \ell}=500 \ldots . \text { (i) }$

$\frac{({n}+1) {V}}{2 \ell}=500 \ldots(ii)$

$(ii)\, (i)$ $\frac{{V}}{2 \ell}=50$

$\ell=\frac{1000}{2 \times 50}=10$

Standard 11
Physics

Similar Questions

Start a Free Trial Now

Confusing about what to choose? Our team will schedule a demo shortly.