Question

By means of diagram show later displacement for a Ray of light rectangular glass block

Answer 1

given here shows the path of a light ray through a rectangular glass( or any refracting material. AB is incident ray. BN is normal to interface between air and the refracting block.<ABN=i is angle of incidence.

At B the ray enters from rarer to denser medium and hence deviates towards the normal.BC shows the refracted ray which makes an angle r with the normal. < r is called angle of refraction.

At C on the opposite surface ,the ray BC emerges from the refractive medium and enters in air medium. Here,CD is called emergent ray. The angle between emergent ray CD and normal CN' is called angle of emergence.

Since, two normals are parallel to each other the angle of refraction at the upper surface is equal to angle of incidence at the lower surface. Therefore, according to Snell's law , the angle of refraction at C must be equal to i.