Question

The length of a sonometer is $1m$ and its mass is $4gm.$ The velocity of transverse wave that travels along this wire when tension in the wire is $2kg.wt$ is

• A. $7m{s}^{-1}$
• B. $14m{s}^{-1}$
• C. $70m{s}^{-1}$
• D. $140m{s}^{-1}$

Answer 1

Answer: (C)

$70m{s}^{-1}$

Tension $=2kg.wt=2\times 9.8N$
$v=\sqrt{\frac{T}{m/l}}$
$=\sqrt{\frac{2\times 9.8}{\frac{4}{1000}\times \frac{1}{1}}}$
$=\sqrt{\frac{2\times 9.8\times 1000}{4}}$
$=70m/s$