Question

What is meant by the statement critical angle for diamond Is 24 degree?

Answer 1

when the light ray passing from diamond to air , incident at the boundary at an angle of incidence equal to 24 degree  , it is refracted along the boundary surface ,that is , the angle of refraction becomes 90 degree . as the sin of the critical angle is equal to the reciprocal of the refractive index of that material .

Answer 2

meaning of this statement is that :-

• Critical angle of diamond is very small

• For TIR to occur , light should fall greater than critical angle

• Since , its critical angle is very small , so TIR takes place which is responsible for shining nature of diamond , thats why diamond shines