The successive resonating frequencies for a stretched wire are 250 Hz and 300 Hz. The wire is stretched between two rigid supports with a tension of 36 N.
If the mass per unit length of the wire is `0.01` kg, then the length of the wire is

Options

A. 40 cm
B. 50 cm
C. 60 cm
D. 70 cm

Answer

C

Explanation

Fundamental frequency ` = 300 - 250 = 50 ` Hz as all harmonics are present .
`n = 1/(2L) sqrt(T/m) `
` :. L = 1/(2m) sqrt(T/m) = 1/(2 xx 50) sqrt(36/(1 xx 10^(-2)) ) = 60/(2 xx 50) = 60/100 m = 60 ` cm