Summary
Highlights
The video discusses what refraction through a glass slab is and its importance for exams. It sets up the scenario with air (rarer medium) and a glass slab ABCD (denser medium), noting that there will be two instances of refraction.
An incident light ray falls on the glass slab. At the point of incidence, a normal is drawn. As the light ray enters from the rarer medium (air) to the denser medium (glass), it bends towards the normal, changing its path.
The light ray then reaches the other side of the glass slab where it encounters another refraction. As it exits from the denser medium (glass) to the rarer medium (air), it bends away from the normal, resulting in the emergent ray.
The video defines the angle of incidence (i), angle of refraction (r), and angle of emergence (e). It explains that the emergent ray is parallel to the extended incident ray but is shifted sideways. This perpendicular distance of the sideward shift (denoted as 'd') is called lateral displacement.
When a light ray enters a glass slab, the emergent ray is parallel to the extended incident ray but is slightly shifted side-ward. This sideward shift is known as lateral displacement, which is the perpendicular distance between the emergent ray and the extended incident ray.