Question

calculate the critical angle for glass air interface if any light incident on glass surface us deviated throgh 15 degree when angle incident is 45 degree

Answer 1

Please find solution

Answer 2

Answer:

45.2 degrees

Explanation:

Given that,

Incident angle i=45  degrees

 Let critical angle be ic

​Now,

sin ic  =μ

Where, μ is the refractive index of glass

Now, again

r=45  degrees − 15  degrees

r=30 degrees

sin r / sin i  =μ

μ=  sin 45  degrees/ sin 30 degrees

μ=  $\sqrt{2}$

μ=1.4

Now, the critical angle is

sin ic  =  1/μ

sin ic  =  1/1.4

ic  = $sin^{-1}$(0.71)

ic  =45.2  degrees

Hence, the critical angle is 45.2  degrees