A ray of light is incident on a boundary between glass and air.
Under which conditions is the ray of light totally internally reflected?
The ray, initially in the air, is incident on the air–glass boundary at an angle of incidence greater than the critical angle.
The ray, initially in the glass, is incident on the glass–air boundary at an angle of incidence greater than the critical angle.
The ray, initially in the glass, is incident on the glass–air boundary at any angle of incidence.
The ray, initially in the air, is incident on the air–glass boundary at any angle of incidence.
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.