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Lighting midterm
quiz one, 2 and chapter 14
55
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Undergraduate 3
02/27/2017

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Term
Daylighting design for climates with lots of clear sky conditions should typically:
Definition
exclude contributions from direct sin to decrease glare and overheating
Term
a heliostat is used in daylighting essentially to
Definition
deliver a concentrated source of daylight
Term
the key to energy savings with daylighting is
Definition
to provide responsive and operable controls for the electric lighting system
Term
assuming a given sky type, daylight factor (DF)
Definition
at a certain point is generally constant throughout the day
Term
the daylight within a building consists of the following componants
Definition
sky component, externally reflected component, internally reflected component
Term
Daylight factor (DF) is expressed
Definition
as a percentage or decimal value
Term
an office building has multiple floors, each with an area of 900 sqft. the following building form is ideal from a daylighting standpoint
Definition
an elongated, narrow plan that maximizes north and south exposure
Term
splaying the walls of a sidelight aperture will:
Definition
reduce the potential for glare
Term
efficacy of a light source is best defined as:
Definition
the ratio of lumens provided to energy used
Term
physical models are used in daylighting design:
Definition
often, they are useful and easy to understand tool
Term
"white" light is composed of:
Definition
a gernerally even mix of light from the visible spectrum
Term
the apparent brightness of an object is dependent upon which of the following?
Definition
The adaptation level of the eye and object luminance
Term
a luminaire is:
Definition
the entire lighting unit
Term
glare is categorized according to which of the following groupings:
Definition
direct glare and reflected glare
Term
light is described as
Definition
a small portion of a continuous range (or spectrum) of electromagnetic radiation
Term
an illuminance meter will provide readouts in which of the following units:
Definition
lux (or footcandles)
Term
the primary nonpersonal factors influencing visual activity include
Definition
object size, contrast, luminance, time permitted for viewing
Term
glare is categorized according to which of the following groupings:
Definition
direct glare and reflected glare
Term
all of the following terms are used to define coloration EXCEPT:
hue
brilliance
opacity
saturation
Definition
opacity
Term
the lumen is
Definition
a measure of photometric power or quantity of light
Term
the inverse square law is
Definition
LUX=cd intensity/distance^2 (The illuminace is inversely proportioned to the square of the distance from the source)
Term
at normal operating temperature, an expected ballast life is:
Definition
12-15 yyears
Term
there are 3 basic types of _______: magnetic, hybrid, and electronic
Definition
LEDs
Term
Organizations involved with ballast standards and testing include:
Definition
ANSI and UL
Term
Which of the following is NOT a characteristic of a light emitting diode? (LED):
Definition
uses a phosphor coating on the lamp interior to produce light
Term
efficacy of a light source is best defined as:
Definition
the ratio of lumens provided to energy used
Term
electric lighting in US nonresidential buildings consumes:
Definition
25%-60% of electric energy utilized
Term
which of the following factors does not need to be considered when determining illuminance requirements for a specific task?
Definition
the color rendering index of the light source
Term
a luminaire that directs 0-10% of its light output toward the ceiling is best classified as
Definition
direct
Term
it is estimated that electric lighting consumes ___ of the total electric power generated in the US
Definition
25%
Term
indirect lighting can accomplish all of the following EXCEPT
Definition
provide adequate illumination for all difficult seeing tasks
Term
the approximate reflectance values for white paint is:
Definition
80-85
Term
Direct glare is caused by light output
Definition
at high angles (i.e. above 45 degrees from the vertical)
Term
the two fundamental functions of a lighting control system are
Definition
to switch or to dim lamps
Term
lighting fixtures typically constitute the following percentage of the overall building budget:
Definition
4-5%
Term
the two most commonly used occupancy sensors for lighting systems are:
Definition
passive infrared and ultrasonic
Term
coefficient of utilization (CU) expresses:
Definition
the ratio of lumens received on a work plane to lumens emitted by lamps in a fixture
Term
the three cavities employed by the lumen (or zonal cavity) method are:
Definition
ceiling, room, and floor cavity
Term
Luminaire efficacy rating (LER) expresses:
Definition
the ratio of lumens having a fixture to watts of energy input
Term
all of the following are primary lighting design considerations, EXCEPT
Definition
the ratio of direct to indirect light
Term
lighting power density is expressed using which of the following units:
Definition
watts per square foot (or square meter)
Term
LED's are growing in popularity as a result of their
Definition
efficient use of power
Term
the relationship between brightness and luminance can best be describes in the following way:
Definition
both are terms used to describe light coming off an object; however, brightness is subjective and luminance is measurable
Term
the SI unit of luminous intensity is the
Definition
candela
Term
illuminance is best defined as
Definition
the density of luminance energy, expressed as lumens per unit area
Term
energy-efficient lamps are typically rated at lower___ than regular lamps
Definition
wattage
Term
Which of the following resents a list of electric lamps properly ordered from lowest to highest luminous efficacy
Definition
incandescent, murcury vapor, fluorescent, low-pressure sodium or incandescent, metal halide, fluorescent, low-pressure sodium
Term
efficacy of a light source is best defined as
Definition
the ratio of lumens provided to energy used
Term
the quartz-iodine lamp is an example of:
Definition
an incandescent lamp
Term
a ballast is required for correct operation of:
Definition
electric (gaseous) discharge lamps
Term
the basic principle of operation of an incandescent lamp is best described as
Definition
electric current heats a filament causing it to emit light
Term
the color rendering index (CRI) of a fluorescent lamp depends upon the:
Definition
phosphor coating applied to the interior of the lamp
Term
an electronic ballast uses solid state components to transform the frequency of the power from 60 Hz to
Definition
20,000 Hz
Term
at normal operating temperature, an expected ballast life is
Definition
12-15 years
Term
the MR-16 lamp is approximately:
Definition
2 inches in diameter
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