Question

What is true for the critical incident angle? A The incident angle is the angle for which the angle of refraction is 90°.

B The incident angle goes from a low to a higher index of refraction.
C The incident angle is not equal to the angle of reflection.
D The incident angle is the angle which results in dispersion.

Answer 1

A The incident angle is the angle for which the angle of refraction is 90°.

Step-by-step explanation:

When the light travels from a high denser medium to a low denser medium, the light bends away from normal. The greater the angle of the incidence, the greater is the angle of the refraction. But, at certain angle, the refraction does not happen and the light got reflected instead to be refracted.

This angle is called critical angle , when the angle of the refraction becomes equal to 90°.