A massless rod BD is suspended by two identical massless strings AB and CD of equal lengths. A block of mass m is suspended at point P such that BP is equal to x, If the fundamental frequency of the left wire is twice the fundamental frequency of right wire, then the value of x is :-

Options

A. `1//5`
B. `1//4`
C. `4l//5`
D. `3l//4`

Answer

5

Explanation

`v = sqrt((T)/(mu)) = sqrt((0.5)/(10^(-3)//0.2)) = 10 m//sec`.
`v = flambda`
`10 = (100)lambda rArr lambda = 0.1 m = 10 cm`
distance between two successive nodes `= (lambda)/(2) = 5 cm`