An optical engineer is testing a new high-purity glass prism for use in a laser-guiding system.
Show, by calculation, that the critical angle c c\,c for this glass prism, which has a refractive index of 1.62, is approximately 38∘ 38^\circ\,38∘ at a boundary with air.
Explain why the refractive index of a material is a dimensionless quantity (has no unit).
Explain why total internal reflection at a boundary with air can only occur if the refractive index of the medium is greater than 1.0.
30 exam-style questions on Edexcel IGCSE Physics Light and sound. Each one has a worked solution and a mark scheme showing where the marks go.