What is the critical angle of a diamond having a refractive index of 2.42? Use air as the second medium. Air has the refractive index 1.00.

A. 14.9°

B. 24.4°

C. 36.6°

D. 40.9°

Given:

refractive index: diamond = 2.42; air = 1

90° should have been provided in the problem. I encountered similar problem before.

Using Snell's Law: n1*sin (a) = n2*sin (b)

where:

n1 and n2 are the refractive indexes

sin (a) and sin (b) are the corresponding angles.

n1 = 2.42

n2 = 1.00

b = 90°

n1 * sin (a) = n2 * sin (b)

2.42 * sin (a) = 1 * 1

2.42 * sin (a) = 1

sin (a) = 1 / 2.42

sin (a) = 24.4° Choice B.