Rays, normals, reflection and refraction
Rays, normals, reflection and refraction

Light is a transverse wave, so its vibrations are at right angles to the direction of energy transfer. In ray diagrams, a ray shows the direction light travels and the normal is a line drawn at 90∘90^\circ90∘ to the surface.
Step-by-step lessons on Edexcel IGCSE Physics Light and sound. Each one builds up to exam-style questions. Build a strong foundation in mechanics and electricity before tackling the more mathematically demanding astrophysics and nuclear topics.