Question

The speed of transverse waves in a stretched string is $700cm/s$. If the string is $2m$ long, the frequency with which it resonates in fundamental mode is

• A. $\frac{7}{12}Hz$
• B. $\frac{7}{4}Hz$
• C. $14Hz$
• D. $\frac{2}{7}Hz$

Answer 1

Answer: (B)

$\frac{7}{4}Hz$

$v=700cm/s$
$l=2m$
fundamental frequency = $\frac{v}{2l}$
$=\frac{700}{2\times 2}\times \frac{1}{100}Hz=\frac{7}{4}Hz$