In Figure, light from ray A refracts from material 1 (n1 = 1.60) into a thin layer of material 2 (n2 = 1.80), crosses that layer, and is then incident at the critical angle on the interface between materials 2 and 3 (n3 = 1.30). (a) What is the value of incident angle θ A?

(b) If θ A is decreased, does part of the light refract into material 3? Light from ray B refracts from material 1 into the thin layer, crosses that layer, and is then incident at the critical angle on the interface between materials 2 and 3.

(c) What is the value of incident angle θ B?

(d) If θ B is decreased, does part of the light refract into material 3?

113 10 n