Question

Write three differences which you observe when a light ray passes through a glass slab and glass prism.

Answer 1

Light ray passes through a glass prism.

• A glass prism is a transparent object having two triangular ends and three rectangular sides. The refraction of light in glass prism is different from a glass slab. This is because in glass prism, the incident ray of light is not parallel to emergent ray of light.
• When a ray of light enters the glass prism it gets deviated two times. First when it enters the glass prism and second when it comes out of the prism. This is because the refracting surfaces of the prism are not parallel to each other.
•  Also, when the ray of light passes through the prism it bends towards its base.

Light ray passes through a glass slab

• Light emerges from the glass slab in direction parallel with that in which it enters the glass slab
•  Perpendicular distance between incident ray and emergent ray coming out of glass slab is called lateral displacement.
• One when it enters the glass slab from air and second time when it enters the air through glass slab. When light rays travelling through air enters glass slab, they get refracted and bend towards the normal.
• Now the direction of refracted ray changes again when it comes out of the glass slab into air.