When a light ray passes through three different media, its path changes due to refraction at each boundary between the media.
Explanation:
- Refraction occurs when light moves from one medium to another with a different optical density.
- The speed of light changes in each medium, causing the ray to bend.
Key Principles:
- Snell’s Law:
n₁ sin i = n₂ sin r
Where:
- n₁, n₂ = refractive indices
- i = angle of incidence
- r = angle of refraction
- Behavior of Light:
- From rarer to denser medium → bends towards the normal
- From denser to rarer medium → bends away from the normal
Path Through Three Media:
- At the first boundary → light refracts
- Travels in second medium → reaches next boundary
- At second boundary → refracts again
- Final path depends on refractive indices of all three media
Special Case:
- If the outer media are the same and surfaces are parallel (like in a glass slab), the emergent ray is parallel to the incident ray but laterally displaced.
Conclusion:
The path of a light ray through three different media involves multiple refractions, determined by the refractive indices and angles at each interface.