Refraction of Light and Optical Lenses

Contents / notes

• Laws of refraction.
• Explanation of refraction in terms of the velocity of light in different media.
• Definition of refractive index.
• Determination of the refractive index of glass and liquids using Snell's law.
• Real and apparent depth and lateral displacement.
• Critical angle and total internal reflection.
• Glass prisms and the minimum deviation formula.
• Types of lenses.
• Lens formula: 1/f = 1/u + 1/v.
• Newton's formula as stated in the source: F² = ab.
• Magnification.

Candidate objectives

• Interpret the laws of refraction.
• Determine the refractive index of glass and liquids using Snell's law.
• Determine the focal length of curved surfaces.
• Determine refractive index using the principle of real and apparent depth.
• Determine the conditions necessary for total internal reflection.
• Examine the uses of periscopes, prisms, binoculars and optical fibres.
• Apply total internal reflection to explain the formation of mirages.
• Use the lens formula and ray diagrams to solve optical numerical problems.
• Determine the magnification of an image.
• Calculate the refractive index of a glass prism using the minimum deviation formula.
• Trace rays through an optical prism.