You are here
When we a say a glass prism, we mean a triangular glass prism
What is a Triangular Glass Prism?
It is a glass object made up of
- 3 Rectangular sides
- 2 Triangular ends
Here, refraction occurs on the two sides of equilateral triangle
We can see that the two faces are not parallel to each other
In a rectangular glass slab (link), the two faces are parallel but in a prism... they are not parallel
What is Refraction of Light in case of Glass Prism
When light ray falls on one side of prism, it gets refracted (bent towards the normal)
It is because it has moved from an optically rarer medium (air) towards optically denser medium (prism)
When these ray reach the other side of prism, it gets refracted again (bent away from normal)
It is because now it has moved from an optically denser medium (prism) towards optically rarer medium (air)
In the figure,
- ∠i – Angle of incidence
- ∠r – Angle of refraction
- ∠e – Angle of emergence
- ∠A – Angle of the prism
- ∠D – Angle of deviation
What are Incident Ray, Refracted Ray and Emergent Ray in Case of Prism
The Light Ray which falls on prism is called Incident ray
The light Ray which is refracted (bent on enterting prism) is called Refracted Ray
Light ray which emrges out of Prism is called Emergent RAY
What is angle of incidence, angle of refraction, angle of emergence and angle of deviation in this case?
Angle of Incidence
The angle between incidence ray and normal ray is called Angle of Incidence
Angle of Refraction
The angle between refracted ray and normal ray is called Angle of Refraction
Angle of Emergence
The angle between emrgent ray and Normal at other side of prism is the angle of emergence
Angle of Deviation
If Incident ray is extended forwards and Emergent ray is extended backwards
They tend to meet at point O
Angle made by emergent ray with the incident ray at this point is called Angle of Deviation
