A ray of light passes from a block of plastic into air. The critical angle for this plastic is 40∘40^\circ40∘.
Which statement is correct?
The angle of refraction is always smaller than the angle of incidence.
If the angle of incidence is 30∘30^\circ30∘, total internal reflection occurs.
If the angle of incidence is 50∘50^\circ50∘, the ray is totally internally reflected.
The angle of incidence is the angle between the light ray and the surface of the plastic block.
100 exam-style questions on CIE IGCSE Physics 3.2.2 Refraction of light. Each one has a worked solution and a mark scheme showing where the marks go.