A beam of light passes from diamond (n=2.42) to air. What is the critical angle?

A beam of light passes from diamond (n=2.42) to air. What is the critical angle?

Step 1: Understand that the critical angle is the angle of incidence above which light cannot pass through a boundary and is instead reflected back.
Step 2: Identify the refractive indices of the two materials involved. Here, diamond has a refractive index (n1) of 2.42 and air has a refractive index (n2) of approximately 1.
Step 3: Use the formula for the critical angle (θc): θc = sin⁻¹(n2/n1).
Step 4: Substitute the values into the formula: θc = sin⁻¹(1/2.42).
Step 5: Calculate the value: θc ≈ sin⁻¹(0.4132).
Step 6: Use a calculator to find the inverse sine: θc ≈ 24.4°.

Refraction and Critical Angle – The critical angle is the angle of incidence above which total internal reflection occurs when light passes from a denser medium to a less dense medium.