The refractive index of a material is 1.5. Calculate the critical angle at the glass-air interface
- 19o
- 21o
- 39o
-
42o
The correct answer is: D
Explanation
Sin C = \(\frac{1}{\eta} = \frac{1}{1.5} = 0.6667\)
C = sin\(^{-1}\) 0.6667
= 42°