Question

A stretched string is $1m$ long. Its linear density is $0.5gm/m$. It is stretched with a force of $20N$. If plucked at a distance of $25cm$ from one end, the frequency of the tone emitted by it is

• A. $100Hz$
• B. $200Hz$
• C. $300Hz$
• D. $400Hz$

Answer 1

The correct option is B $200Hz$

Given$:-$

$M=0.5gm/m=5\times {10}^{-4}kg$

$v=\frac{2}{2l}\sqrt{\frac{T\times l}{M}}$

$or,v=\sqrt{\frac{T}{Ml}}=\sqrt{\frac{20}{5\times {10}^{-4}\times 1}}$

$=\sqrt{4\times {10}^4}Hz=200Hz$

Hence,

option $\left(B\right)$ is correct answer.