What is the meant by the statement ‘the critical angle for diamond is 24°?
What is the meant by the statement ‘the critical angle for diamond is 24°?

Solution:

The phrase “the critical angle for diamond is 24° suggests that at a 24° incidence angle, the angle of refraction in the air will reach 90° within the diamond. When the incidence angle exceeds the refraction angle, the beam undergoes entire internal reflection with no refraction.