Light and Optics Quiz

Light and Optics

• Light is electromagnetic radiation that travels as a transverse wave.
• It exhibits wave-particle duality, meaning it can behave as both a wave and a particle.
• Light travels in straight lines, and is a disturbance in electric and magnetic fields.
• Speed of light in a vacuum is approximately 300,000 km/s (or 3 x 10⁸ m/s).
• Light is created by vibrating electrons.
• The electromagnetic spectrum encompasses various types of light, each with different frequencies and wavelengths.
• The visible spectrum, a small portion of the electromagnetic spectrum, is ROYGBIV (Red, Orange, Yellow, Green, Blue, Indigo, Violet).
• The wave equation relates wave speed, frequency, and wavelength (v = fλ).
• Various technologies, like Wifi, Bluetooth, and cellular signals, utilize forms of electromagnetic radiation.
• Additive colour mixing involves combining coloured lights. Red, green, and blue (RGB) are primary colours.
• Subtractive colour mixing involves combining coloured pigments or filters, where specific colours of light are absorbed.
• Examples of colour mixing are explained for light and objects using primary and secondary colours such as cyan, magenta, and yellow.
• Light sources include incandescent, bioluminescence, chemiluminescence, triboluminescence, fluorescent, LED, the sun, and lightning.
• Light phenomena include transparency, translucency, and opacity.
• Reflection of light occurs, including regular reflection (mirrors) and diffuse reflections (other objects).

Mirrors

• Mirrors can be regular or curved (concave or convex)
• Concave mirrors can produce various image types (upright, inverted, real, virtual) The size of an image can be larger or smaller than the object.
• Convex mirrors always produce virtual images that are smaller than the object.
• Ray diagrams are used to illustrate how light interacts with flat and curved mirrors.
• Magnification (M) is calculated by the ratio of image height to object height (or image distance to object distance).
• Magnification is equal to the height of the image (hi) divided by the height of the object (ho)

Refraction

• Refraction is the bending of light as it passes from one medium to another.
• Refraction occurs due to a change in the speed of light in different mediums.
• Examples of refraction include rainbows, mirages, shimmering stars, and dispersion, including the "breaking" effect of a straw in a glass of water.
• The index of refraction (n) is a measure of how much a medium slows down light.
• Ray diagrams can be used to depict how light rays refract when moving from one medium to another. Total internal reflection is a special type of refraction where light is reflected back into the denser medium when the angle of incidence exceeds the critical angle.
• Snell's Law describes the relationship between the angles of incidence and refraction, and the refractive indices of the two mediums where n₁ sin θ₁ = n₂ sin θ₂

Lenses

• Lenses can be converging (convex) or diverging (concave).
• Converging lenses cause light rays to converge (come together).
• Diverging lenses cause light rays to diverge (spread apart).
• Ray diagrams can be used to illustrate how light interacts with lenses, forming images.
• The human eye has features similar to a converging lens.
• Defects include short-sightedness (myopia), long-sightedness (hyperopia), and astigmatism.
• Various technologies utilize lenses, including eyeglasses, cameras, telescopes, magnifying glasses, projectors, binoculars, and laser pointers.