Critical angle of diamond is

The correct answer is 24.4°.

 Key Points

• The critical angle of a diamond is 24.4°. This refers to the smallest angle of incidence at which total internal reflection occurs.
• The critical angle is the angle of incidence that provides an angle of refraction of 90 degrees.
• A light ray entering a diamond at an angle greater than 24.4 degrees to the normal will undergo total internal reflection.
• This property of a high refractive index and low critical angle allows the diamond to exhibit high brilliance and sparkle, as light entering the diamond undergoes multiple total internal reflections.

 Additional Information

• The critical angle for any material depends on its refractive index.
• The refractive index is a measure of how much the speed of light is reduced within the medium compared to the speed of light in a vacuum.
• Materials with a higher refractive index have a lower critical angle, meaning light will be totally internally reflected at smaller angles.