Total internal reflection ( Refraction and Total internal reflection)

This slides are about total internal reflection

1. TOTAL INTERNAL REFLECTION LW MMOTLA

2. RECAP OF REFRACTION Refraction is the bending of light as it moves from one medium to another. Key terms: Incident ray – the incoming ray of light Refracted ray – the bent ray as light enters the second medium Normal – an imaginary line perpendicular to the surface Refraction occurs when light passes from a less dense to a more dense medium or vice versa. Angle of incidence ≠ angle of refraction

3. QUICK QUESTION IMAGINE YOU ARE UNDER WATER IN A POOL, WHY DO YOU WHEN YOU TRY TO LOOK IN THE SKY , YOU DON’T SEE THE SKY BUT RATHER YOUR REFLECTED IMAGE

4. TOTAL INTERNAL REFLECTION TOTAL INTERNAL REFLECTION REFERS TO When light reflects entirely back into the medium instead of refracting, because the angle of incidence is greater than the critical angle.

5. The conditions for total internal reflection are: light is travelling from an optically denser medium (higher refractive index) to an optically less dense medium (lower refractive index). the angle of incidence is greater than the critical angle

6. QUIZ Question 1: Which of the following is necessary for Total Internal Reflection to happen? a) Light must pass from air into glass b) Light must pass from a denser medium to a less dense medium c) Light must travel in a vacuum QUESTION 2 What happens to the light during Total Internal Reflection? a) It passes through into the second medium b) It bends toward the normal c) It reflects completely back into the original medium

7. CRITICAL ANGLE CRITICAL ANGLE REFERS TO The smallest angle of incidence at which the refracted ray skims along the surface. It only occurs from denser to less dense medium Beyond this angle, the concept of total internal reflection occurs

8. CONCLUSION Total Internal Reflection (TIR) occurs when light reflects entirely within a denser medium, rather than refracting out. It only occurs when : Light moves from a denser medium to a less dense medium The angle of incidence is large enough 🔹 In TIR, no light exits — all of it reflects.