Question
Question: A glass prism of refractive index 1.5 is immersed in water (R.I. = 4/3). The beam of light incident ...
A glass prism of refractive index 1.5 is immersed in water (R.I. = 4/3). The beam of light incident normally on the face AB is totally reflected to reach the face BC, if
A
Sin θ≥ 8/9
B
Sin θ< 2/3
C
2/3 < Sin θ< 8/9
D
None of these
Answer
None of these
Explanation
Solution
The light ray is just reflected internally at the point P (say). Therefore the critical angle ≅ θ. Applying Snell’s Law of refraction at the critical angle of incidence (θ) we obtain
⇒ sin θ = 98
