A sheet of plate glass of uniform thickness is placed over a sheet of fine graph paper
PHYSICS · Multi-part · CBSE · Physics · Light — Reflection and Refraction · Light — Reflection and Refraction
Problem
A sheet of plate glass of uniform thickness 5.0cm is placed over a sheet of fine graph paper. When the graph paper is viewed vertically from above, the markings appear displaced downwards by 3.3cm. When the same paper is viewed along a direction that makes an angle of 35∘ with the normal to the glass surface, the point on the paper that lies directly under the point of observation appears shifted sideways by 2.8cm from its original position.
(i) Derive an expression for the lateral shift S produced when light passes obliquely through a plane parallel slab of thickness t and refractive index n.
(ii) Using the given data for vertical viewing, calculate the refractive index of the glass slab.
(iii) Employ the expression derived in part (i) to verify whether the sideways shift observed at 35∘ agrees with the refractive index obtained in part (ii).