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. `sinthetage(8)/(9)`
B. `(2)/(3)ltsinthetalt(8)/(9)`
C. `sinthetale(2)/(3)`
D. None of these

Answer

A

Explanation

The phenomenon of total internal reflection takes place during reflection P.
`sintheta=(1)/(_g^wmu)`… (i)
Now, `_g^wmu=(_g^amu)/(_w^amu)=(1.5)/(4/3)=1.125` :' `sintheta=(1)/(1.125)=(8)/(9)` :' `sintheta` should be greater than ` 8/9.