Question

In an experiment it was found that when a sonometer in its fundamental mode of vibration and a tuning fork gave $5$ beats when length of wire is $1.05$ metre or $1$ metre. The velocity of transverse waves in sonometer wire when its length is 1m

• A. $400m/s$
• B. $210m/s$
• C. $420m/s$
• D. $450m/s$

Answer 1

The correct option is C $420m/s$

${\delta }_1^s-{\delta }_2^s=2\times beat$
$=2\times 5$
$=10$

$\delta =\frac{v}{2l}$

$\frac{v}{2l_1}-\frac{1}{2\left(1.05\right)}=10$

$v(\frac{1}{2\left(1\right)}-\frac{1}{2\left(1.05\right)})=10$

$v=\frac{10\times 2\times 1\times 1.05}{0.05}$ $=420m/s$