A glass prism of refractive index 1.5 is immersed in water (refractive index 4/3). A light beam incident normally on the face AB is totally reflected to reach on the face BC if.

Options

A. `sin theta ge 8//9`
B. `2//3 lt sin theta lt 8//9`
C. `sin theta le 2//3`
D. It is not possible

Answer

A

Explanation

For TIR at `AC`
`thetagtC`
`=sin thetagesin Cimpliessin thetage(1)/(._(w)mu_(g))`
`impliessin thetage(mu_(w))/(mu_(g))impliessin thetage(8)/(9)`