REFRACTION THROUGH A RECTANGULAR GLASS SLAB CLASS 10 CHAPTER 10

REFRACTION THROUGH A RECTANGULAR GLASS SLAB

Consider a rectangular slab. A ray of light AO is incident on the glass surface at O. 

As the ray AO enters from air(rarer medium) to glass(denser medium), the ray 

bends towards normal and follows the path OB inside the glass slab. At the point 

B the ray enters from glass (denser medium) to air (rarer) medium. Then the ray 

bends away from the normal and follows the path BC outside the glass slab. In the 

figure, AO is the incident ray, OB is the refracted ray, and BC is the emergent ray.

The emergent ray BC will be parallel to the incident ray AO. The perpendicular 

distance between the original path of the incident ray and the emergent ray is 

called the lateral displacement.

Here the ray of light bends twice. First time when the light ray enters from air to 

the glass slab, it bends towards the normal, ie from rarer to denser medium.

Second time when the ray moves out from the glass to air, it bends away from the 

normal, ie it moves from denser medium to rarer medium.

*******************************************************************