The angle that a straight line, such as a ray of light falling on a surface, makes with a normal to the surface at the point of incidence

• Angle of incidence

• Angle of reflection

• Angle of refraction

The angle that a reflected ray makes with a normal to a reflecting surface at the point of incidence

• Angle of incidence

• Angle of reflection

• Angle of refraction

The principle that when light or sound is reflected from a smooth surface, the angle of incidence is equal to the angle of reflection, and the incident ray, the reflected ray, and the normal to the surface all lie in the same plane

• Law of incidence

• Law of reflection

• Law of refraction

The angle that a refracted ray makes with a normal to the interface between two media at the point of incidence

• Angle of incidence

• Angle of reflection

• Angle of refraction

A device for maintaining the current through a fluorescent or HID lamp at the desired constant value, and sometimes also providing the required starting voltage and current

• Ballast

• Starter

• Phosphor

• Fluorescence

A device used with a ballast to provide the starting voltage for a pre-heat fluorescent lamp

• Triphosphor

• Starter

• Phosphor

• Fluorescence

Any of a number of substances that emit light when excited by radiation

• Ballast

• Starter

• Phosphor

• Fluorescence

A phosphor having peaks in three specific color regions, red, blue, and green, used to improve the color rendering of a fluorescent lamp

• Ballast

• Starter

• Triphosphor

• Fluorescence

The emission of radiation esp. of visible light, by a substance during exposure to external radiation

• Ballast

• Starter

• Triphosphor

• Fluorescence

The temperature at which a blackbody emits light of a specified spectral distribution, used to specify the color of a light source

• Color temperature

• Spectral distribution curve

• Color rendering index