A hollow pipe of length `0.8m` is closed at one end. At its open end a `0.5 m` long uniform string is vibrating in its second harmonic and it resonates with the fundamental frequency of the pipe. If the tension in the wire is `50 N` and the speed of sound is `320 ms^(-1)`, the mass of the string is

Options

A. `5g`
B. 10g
C. 20g
D. 40g

Answer

B

Explanation

`(V_s)/(4 L_(P))=(2)/(21_s)sqrt((T)/(mu))implies (320)/(4xx0.8)=1/0.5sqrt((50)/(mu))implies mu=1//50`
Mass of string,`m=mu1_s=1/50xx0.5=0.01 kg =10g`