Question

a ray of light shown below is incident upon a glass equilateral prism n=1.5
determine the angle of exiting light theta

Answer 1

Answer:

Explanation:

Given: A ray of light fall normally on the face of a glass prism (n=1.5).  

To find the angle of prism, if the ray just fails to emerge from the second surface

Solution:

As ray of light falls normally, it goes undeviated,  

So angle of refraction, r  1 =0

If the ray is not able to emerge, it means that the angle of refraction is equal to 90 degrees, and  r  2 is critical angle for prism as the refracted ray grazes the surface.

So  μ=  sinC/ 1

​

 

⟹sinC=  1.5 /1

​ ⟹C=sin  −1  =0.67

⟹C=41.81  

∘

 

And Refracting angle, A=r  1  +r  2  =0+41.81=41.8   is the angle of the prism.

Answer 2

Answer:b

Explanation: