A horizontal glass slab of uniform thickness (index of refraction ) is submerged so…
PHYSICS · Multi-part · CBSE · Physics · Light — Reflection and Refraction · Light — Reflection and Refraction
Problem
A horizontal glass slab of uniform thickness t=2.0cm (index of refraction ng=1.50) is submerged so that its top surface is in contact with air (nair=1.00) and its bottom surface is in contact with fresh water (nw=1.33). A narrow laser beam in the air strikes the top surface of the slab at an angle of 35∘ relative to the normal.
(1) Calculate the angle that the beam makes with the normal while it is inside the glass slab.
(2) Calculate the angle that the beam makes with the normal after it exits the slab and travels in the water.
(3) Derive an expression for the lateral displacement d between the point where the beam would have struck the bottom surface had it continued in a straight line through the air–water interface and the actual point where it emerges into the water. Then determine the numerical value of d for the given parameters.
(4) Qualitatively describe how the lateral displacement would change if the glass slab were replaced by a material of higher index of refraction while all other conditions remained the same.