Question

define critical angle and total internal refraction

Answer 1

Critical angle : the angle of incidence beyond which rays of light passing through a denser medium to the surface of a less dense medium are no longer refracted but totally reflected.




Internal refraction : Total internal reflection is the phenomenon which occurs when a propagated wave strikes a medium boundary at an angle larger than a particular critical angle with respect to the normal to the surface. ... The critical angle is the angle of incidence above which the total internal reflection occurs.

Answer 2

total internal reflection is the phenmenon which occurs when a propagated wave strikes a medium boundry at an angle larger than a particular critical angle with respect to the normal to the surface