A ray of light from a denser medium strikes a rarer medium at angle of incidence i. The reflected and refracted rays make an angle of 90° with each other. The angles of reflection and refraction are r & r ′ ′ respectively. The critical angle is
Text Solution
Verified by ExpertsA
Applying Snell’s Law for refraction,
…(1)
From the given condition, r + r ′ ′ = 90
⇒ ⇒ Sin r ′ ′ = Cos r …(2)
Solution of (1) and (2) yields, 
…(3)
Since, at the time of total internal reflection
According to the Law for refraction;
i = r …(4)
Using (3) and (4) we obtain
⇒ ⇒ tan i = 
….(5)
Sin θ θ c = 
, Using (5) we obtain θ θ c = sin -1 (tan r)
Prepare Smarter with CGP Edu
Get practice questions, solutions, and test series in one place.
Write a Review
Share your experience with this question and solution.
Commentary
Send your comment, doubt, correction, or feedback to admin.
Similar Questions
Explore conceptually related problems