The change in direction of a beam of light as it travels from one material to another is called refraction. The normal is a construction line drawn at right angles to the surface of the glass block.

The beam should be straight in the top and bottom segments, and bend down in the middle. In a gradient, light bends towards the higher-index part, as the law of refraction predicts, or according to ...

The formulas are covered for topics such as light reflection and refraction, electricity, and magnetism. Lens formulas, mirror formulas, potential differences, magnification, Snell’s law of ...