Diamond has an index of refraction of 2.419. What is the critical angle for internal reflection inside a diamond that is in air? A) 155° B) 105° C) 48.8° D) 24.4° E) 131°

C) 24.4°

Explanation:

let nd = 2.419 be the index of refraction of diamond and na = 1.0 be the index of refraction of air and ∅c be the critical angle.

according to Snell's Law:

sin (∅c) = na/nd

sin (∅c) = (1.0) / (2.419)

∅c = 24.4°