A sonometer wire of length `0.7` m is stretch by a weight of 4 kg. what is the linear density of the material of the wire, if its fundamental frequency is 200 Hz?

Options

A. `5xx10^(-3) kg//m`
B. `5xx10^(-4) kg//m`
C. `8xx10^(-4) kg//m`
D. `8xx10^(-3) kg//m`

Answer

B

Explanation

`n = 1/(2L) sqrt(T/m) :. n^(2) = T/(4L^(2)m)`
` :. n = T/(4L^(2) n^(2))`
` = (4 xx 9.8)/(4 xx 7 xx 7 xx 10^(-2) xx 4 xx 10^(4)) = 5 xx 10^(-4) ` kg/m