Question

A guitar string is $90cm$ long and has a fundamental frequency of $124Hz$. To produce a fundamental frequency of $186Hz$, the guitar should be pressed at ?

• A. $60cm$
• B. $30cm$
• C. $20cm$
• D. $10cm$

Answer 1

Answer: (A)

$60cm$

Here, $L_1=90cm,{\upsilon }_1=124Hz,{\upsilon }_2=186Hz,L_2=?$
According to the law of length, ${\upsilon }_2{L}_2={\upsilon }_1{L}_1$
$\therefore {\upsilon }_2=\frac{{\upsilon }_1{L}_1}{{\upsilon }_2}=\frac{124\times 90}{186}=60cm$