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

The phenomenon of total internal reflection takes place during reflection at P.sinθ=1 gwμwhere θ is the angle of incidence at P. Now, gwμ= ah gaμ=1.54/3=1.125Putting in (i), sin θ=11.125=89Therefore, sin θ should be greater than 89