NCCER ELECTRICAL LEVEL 2 MODULE 3 PRACTICE QUESTIONS AND ANSWERS

Light energy that is NOT absorbed by an object can be _____. reflected from and/or transmitted through the object A light that is considered warm in tone is produced by lamps with color temperatures of _____. 3,000°K The resistance of a tungsten filament is ______. much higher after the lamp is turned on The filament of a tungsten-halogen lamp is encased in a capsule containing iodine or _____. bromine gas During operation, a high-output (HO) fluorescent lamp typically has a current draw of _____. 800mA to 1,000mA The type of high-intensity discharge (HID) lamp that uses the oldest HID technology is the _____. mercury vapor lamp The diameter of a 4', T-12 fluorescent lamp is __. 1 ½" To improve both ballast efficiency and lamp efficacy, an electronic ballast typically operates the connected fluorescent lamps at a frequency of _____. 20kHz to 50kHz A driver supplies stable power to a(n) _____. LED Most code requirements governing the installation of luminaries, lampholders, and lamps are covered in _____. NEC Article 410 Luminaire whips used to connect from a junction box mounted above the ceiling to a luminaire installed in a suspended ceiling must have a minimum length of ____. 18" (450 mm) The maximum luminaire whip lengths when wiring suspended ceiling luminaires is ____. 6' (1.8m) Suspended luminaires used in commercial and industrial buildings are supported by the ___. building's structural members When installed on a wall, the track for track lighting must be a minimum of _____. 5' (1.5m) above the finished floor When cutting the branch circuit wires in an outlet box in preparation for connecting a light fixture the amount of free conductor length that should be left after it emerges from the cable raceway is 6" (150mm) _____ is light that hits a surface or object, regardless of the source of this light. Incident light Color temperatures of ______ and lower are described as warm in tone and slightly enhances reds and yellows. 3,000°K A color temperature of _____ is considered moderate in tone, producing a balance between warmth and coolness. 3,500°K Color temperatures of _____ and higher are considered cool in tone, slightly biased toward blues and greens. 4,100°K (CRI) Color Rendering Index When light energy is absorbed by an object, it is stored in the form of ______. heat Light-colored or highly polished surfaces ________. reflect more light than darker-colored or dull surfaces All objects absorb light of different wavelengths in different proportions. This is called _____. selective absorption Cone cells are ____. sensitive to different colors Colored objects owe their color to selective? absorption The lamp with the shortest life expectancy is the _______. incandescent lamp A ballast is used to _____. regulate the current in a fluorescent lamp Surface-mounted luminaires are _____. directly mounted on a ceiling or wall. They can be incandescent, fluorescent, LED, or HID types Recessed luminaires are ____. mounted into ceiling recesses so that the main body of the luminaire is not visible Suspended luminaires are ____. hung from a ceiling using a chain, aircraft wire, cord, or metal stem Track-Mounted lighting systems include _____. track, an electrical feed box, and one or more luminaires of various types that can be positioned along the track Fluorescent or LED troffers are typically a type of _____. recessed luminaire Which of the following is the best tool for opening a luminaire cartoon? Utility knife Unless otherwise marked, boxes for indoor ceiling-mounted luminaires can support a luminaire weighing no more than ___. 50lbs Which type of lamp is subject to an explosion if the arc tub ruptures? Metal Halide lamp Which HID lamp has excellent color rendition? Metal Halide lamp Recessed luminaires that contain lamps of the wrong wattage may cause the lamp to ___. cycle on and off _____ is the intensity of light traveling in a given direction from any surface. Luminance Light enters the eye through the ___. cornea Light impulses are transferred from the eye to the brain by the part of the eye called? optic nerve What surface materials reflects the most light and what absorbs the most light? White plaster(Reflects), Dark red bricks(Absorbs) A total of six colors(violet blue green yellow orange red) are visible when passing white light. Through a prism In 2007, the United States Congress passed the Energy Independence and Security Act (EISA), which mandated a phased elimination of ____. general-use incandescent lamps in 40w-100w sizes