Light travels more slowly in glass than in air. Light travels even more slowly in diamond than in glass.
Explain, in terms of speed, why a ray of light changes direction when it enters glass at an angle to the normal.
The critical angle of diamond is 24∘24^{\circ}24∘. The critical angle of glass is 42∘42^{\circ}42∘.
A cut diamond and a glass copy of exactly the same shape are placed side by side in white light.
Explain why the diamond sparkles much more than the glass copy.
Suggest how the critical angle of a material is related to the speed of light in that material.
93 exam-style questions on Edexcel GCSE Physics 5.1 Reflection, refraction and lenses, covering 5.1.1 Reflection, refraction and total internal reflection, 5.1.2 Specular and diffuse reflection, 5.1.3 Colour of light: absorption and filters, 5.1.4 Lenses: power, focal length and shape, 5.1.5 Ray diagrams for converging and diverging lenses, and 5.1.6 Real and virtual images. Each one has a worked solution and a mark scheme showing where the marks go.