Revision Definitions - Waves and Optics

Vocabulary flashcards based on lecture notes covering key definitions in waves, electromagnetic spectrum, reflection, refraction, and lenses.

Electromagnetic waves

Transverse waves that transfer energy from the source to an absorber.

Electromagnetic spectrum

A family of 7 electromagnetic waves arranged in order of frequency and wavelength.

Continuous spectrum

A continuous range of electromagnetic radiation frequencies without gaps or individual lines.

Luminous object

An object that emits its own light.

Non-luminous object

An object that does not emit its own light.

Transparent medium

A medium that allows light to pass through clearly.

Translucent medium

A medium that allows light to pass through partially while scattering it.

Opaque medium

A medium that does not allow light to pass through.

Visibility of a non-luminous object

A non-luminous object can only be seen if it reflects light from a luminous source.

Ray diagram

A diagram using straight lines with arrowheads to represent the path and direction of light rays.

Wavelength ($\lambda$)

The distance between two consecutive identical points on a wave, such as peak to peak or crest to crest.

Frequency ($f$)

The number of waves passing a point per second, measured in Hertz ($Hz$).

Period ($T$)

The time taken for one complete wave to pass a point.

Amplitude

The maximum displacement of a point on a wave from its rest position.

Regular (specular) reflection

Reflection from a smooth surface where light rays are reflected evenly in one direction.

Diffuse reflection

Reflection from a rough surface where light rays are scattered in different directions.

Law of reflection

The angle of incidence ($i$) is equal to the angle of reflection ($r$).

Refraction

The bending of light as it passes from one medium into another of different optical density.

Dispersion

The separation of white light into its component colors (spectrum) when passing through a transparent medium such as a prism.

Convex lens

A lens that curves outwards and is thicker in the middle, converging light rays to a focal point; used to correct hyperopia.

Concave lens

A lens that curves inwards and is thinner in the middle, diverging light rays; used to correct myopia.