A ray diagram showing refraction at the boundary between air and glass Refraction can cause optical illusions as the light waves appear to come from a different position to their actual source ...

In all ray diagrams, all angles of incidence and refraction are measured between the ray and the normal. Watch this video for a practical demonstration of measuring the refractive index of glass.

10. Draw the ray diagram of image formation when the object is kept at 2F, of the convex lens. With the help of the ray diagram, mention the position and nature of the image formed.