Light is travelling through air. It strikes a plastic block at an angle of incidence of 40∘40^\circ40∘. The plastic has a refractive index of 1.5.
What is the angle of refraction of the light as it enters the plastic?
22∘22^\circ22∘
25∘25^\circ25∘
30∘30^\circ30∘
74∘74^\circ74∘
216 exam-style questions on CIE IGCSE Physics 3.2 Light, covering 3.2.1a Reflection of light, 3.2.1b Images in a plane mirror, 3.2.2 Refraction of light, 3.2.2a Refraction of light, 3.2.2b Total internal reflection, 3.2.2c Refractive index and critical angle, 3.2.2d Optical fibres, 3.2.3a Converging and diverging lenses, 3.2.3b Ray diagrams and the nature of images, 3.2.3c Virtual images and the magnifying glass, 3.2.3d Correcting long-sightedness and short-sightedness, and 3.2.4 Dispersion of light. Each one has a worked solution and a mark scheme showing where the marks go.