Which statement is correct?
The speed of light in a medium is equal to the speed of light in a vacuum multiplied by the refractive index of the medium.
The wavelength of light in a medium is equal to the wavelength of light in a vacuum divided by the refractive index of the medium.
Total internal reflection can occur when light travels from a medium of lower refractive index to a medium of higher refractive index.
The angle of refraction is proportional to the angle of incidence.
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.