A scanning device sends a ray of light through a flat transparent protective window and out into the air. The speed of the light changes as it leaves the window. The window can be tilted so that the ray meets its outer surface with an angle of incidence of 0°, 30°, 60° or 90°. Which angle of incidence should be used so that the ray does not change direction as it leaves the window?
An angle of incidence of 60°
An angle of incidence of 90°
An angle of incidence of 0°
An angle of incidence of 30°
93 exam-style questions on AQA GCSE Physics 6.2 Electromagnetic waves, covering 6.2.1 Types of electromagnetic waves, 6.2.2 Properties of electromagnetic waves 1, 6.2.3 Properties of electromagnetic waves 2, 6.2.4 Uses and applications of electromagnetic waves, 6.2.5 Lenses, and 6.2.6 Visible light. Each one has a worked solution and a mark scheme showing where the marks go.