Solution

Given,

The mass per unit length = 10^-3 Kg/m
Load (m) = 4kg
Fundamental frequencies of vibration (f) =?
Length of the wire (l) = 1m

We have,

\(f=\frac1{2l}\sqrt{\frac T\mu}\)        
\(=\frac1{2\times1}\sqrt{\frac{4\times10}{10^{-3}}}\)
= 100 Hz

Hence the fundamental frequency of the wire is 100 Hz.