If sound travelling at `340ms^(-1)` enters water where its speed becomes `1480 ms^(-1)` , then critical angle for total internal reflection is

Options

A. `13.3^(@)`
B. `89.7^(@)`
C. `86.7^(@)`
D. `10.3^(@)`

Answer

A

Explanation

We have ,
`sinC=(1)/(mu)`
But `mu=(v_2)/(v_1)=(1480)/(340)`
`therefore sin C=(340)/(1480)`
or `C=sin^(-1)((340)/(1480))=13.28^(@)prop 13.3^(@)`.