Light enters an optical fiber made of glass from air at an angle of incidence of 50∘50^\circ50∘. The angle of refraction in the glass is 30∘30^\circ30∘.
The speed of light in air is 3.0×108 m/s3.0 \times 10^8\text{ m/s}3.0×108 m/s.
Determine the speed of light in the optical fiber.
Describe how optical fibers are used in modern communication systems.
216 exam-style questions on CIE IGCSE Physics 3.2 Light, covering 3.2.1a Reflection of light, 3.2.1b Images in a plane mirror, 3.2.2 Refraction of light, 3.2.2a Refraction of light, 3.2.2b Total internal reflection, 3.2.2c Refractive index and critical angle, 3.2.2d Optical fibres, 3.2.3a Converging and diverging lenses, 3.2.3b Ray diagrams and the nature of images, 3.2.3c Virtual images and the magnifying glass, 3.2.3d Correcting long-sightedness and short-sightedness, and 3.2.4 Dispersion of light. Each one has a worked solution and a mark scheme showing where the marks go.