RAY OPTICS 9

Total Internal Reflection (TIR)

Module 1: Conditions for Total Internal Reflection

Total Internal Reflection (TIR) occurs when light travels from a denser medium to a rarer medium and:

1. The angle of incidence exceeds the critical angle.
2. The light must travel from a medium of higher refractive index to one with a lower refractive index.

The critical angle \( \theta_c \) is given by:

\[ \sin \theta_c = \frac{n_2}{n_1} \]

Where \( n_1 \) and \( n_2 \) are the refractive indices of the denser and rarer media, respectively.

1. What are the necessary conditions for TIR?

2. TIR can only occur when light:

3. The critical angle depends on:

4. The critical angle for glass-air interface is approximately:

5. Which equation represents the critical angle?