In Melde's experiment if there are two loops for one meter length in the longitudinal position, calculate the tension in the string. [Frequency of the fork is 128Hz and mass per unit length of the string is `5 xx 10^(-6)kg]`. What will happen if the fork's is rotated through `90^@]`.

Explanation

In the longitudinal position the frequency N of the string is half that of the fork, i.e, `N=(128)/2=64Hz`
Length of the string =1m
Mass per unit length `=mu=5 xx 10^(-6)kg`
Number of segments =p=2
`N=p/(2l) xx sqrt(T/mu)`
`64=(2)/(2 xx l) sqrt((T)/(5 xx 10^(-6))`
T=2.048 N
When the fork is rotating through `90^@`, the string will vibrate in 4 segments with the same frequency as that of the fork.