A ray of light incident at an angle \(\theta\) in a rectangular prism grazes the surface of the prism on emerging from the prism. Determine the value of the angle. [Absolute refractive index of the material of the prism is 1.5]
-
41.8°
- 48.2°
- 60.8°
- 90.0°
The correct answer is: A
Explanation
\(\eta = \frac{1}{sin\theta}\)
\(1.5 = \frac{1}{sin\theta}\)
\(sin\theta = \frac{1}{1.5} = 0.667\)
\(\theta = sin^{-1}(0.667) = 41.835°\)
\(\approxeq 41.8°\)