Q19E

Question

A ray of light is traveling in a glass cube that is totally immersed in water. You find that if the ray is incident on the glass– water interface at an angle to the normal larger than 48.7°, no light is refracted into the water. What is the refractive index of the glass?

Step-by-Step Solution

Verified
Answer

The refractive index of glass is 1.7743.

1Step 1: Snell’s Law


Snell's law determines the degree of refraction as well as the relationship between the angle of incidence, angle of refraction, and refractive indices of two media.


 

        


Here;

 

 

        



Critical Angle-Beyond which light rays traveling through a thicker media to the surface of a less dense medium are no longer refracted but completely reflected

Total Internal Reflection-When the angle of incidence surpasses the critical angle, a light ray reaches an interface with less dense material and is completely reflected.

2Step 2: Refractive Index of the glass

Light traveling from glass to water

Medium 1 is glass

Medium 2 is water



Applying Snell’s law;


Hence, the refractive index of glass is 1.7743.