When we see a letter written on a paper through a rectangular glass slab, it appears to be raised. This is a phenomenon that can be explained with the help of ray diagrams.


The phenomenon of raised letters can be understood by the principle of refraction of light. When light passes from one medium to another, its speed changes, and it bends. This bending of light is known as refraction.


A ray diagram is a graphical representation of the path of light as it travels through a medium. It is a useful tool for understanding the behavior of light as it passes through different media.


To understand the phenomenon of raised letters, we can perform the following experiment:

1. Place a rectangular glass slab on a sheet of paper with some letters written on it.


2. Observe the letters through the glass slab from the top.

When we observe the letters through the glass slab, the light from the letters enters the glass slab, where it undergoes refraction. The glass slab is a denser medium than air, so the light slows down and bends towards the normal. As a result, the letters appear to be raised.


In conclusion, the phenomenon of raised letters through a rectangular glass slab can be explained by the principle of refraction of light. The glass slab slows down the light, causing it to bend towards the normal, resulting in an apparent raising of the letters.