A string of length `0.4 m` and mass `10^(-2)kg` is tightly clamped at its ends. The tension in the string is `1.6 N`. Identical wave pulse are produced at one end at equal intervals of time, `Deltat`. The minimum value of `Deltat` which allows constructive interference of successive pulse is

Options

A. 0.05s
B. 0.10s
C. 0.20s
D. 0.40s

Answer

B

Explanation

Velocity of wave :`v=sqrt((T)/(m))=sqrt((1.6)/(10^(-2)//0.4))=8 m//s`
The wave wil be in same phase after traveling a distance at of ` 21 =2xx0.4=0.8m` and distance interfernce will take place. So time `trianglet`
`trianglet=(0.8)/(v)=(0.8)/(8)=0.10 s`