Light_Vocabulary

//NEW VOCABULARY. LIGHT//


 * Alternating Current (AC)**: the flow of electricity (electric current) in a circuit that frequently alternates direction every second. In the USA, the standard frequency of alternating current is 60 Hz (hertz or cycles/second) and AC (as opposed to direct current) is generally the method for delivering electric power to homes and buildings.


 * Accent Lighting**: lighting that is used to accent or highlight a particular object such as a work of art. To be effective accent lighting should be approximately four or five times the level of ambient light in the room, area, or space. House plants can be accented by aiming an uplight at the wall behind the plant, creating a dramatic silhouette of the plant against the wall.


 * Ballast**: an electrical device used with fluorescent and HID lamps to supply sufficie nt voltaje to start and operate the lamp but then limit the current during operation.


 * Bollard**: an outdoor luminaire that is a short (usually about 2-4 feet in height) but very sturdy vertical post with the light source located at or near the top. Bollards are typically used to light walkways in commercial settings.


 * Brick Light**: a light fixture (usually the size of a brick) that can be recessed in a brick wall with its face parallel to the surface of the brick surface in order to light a walkway, a step, a landing, or a path.


 * Candela**: a unit of light measurement that refers to the luminous intensity from a light source a specific direction. light source