ET 3 EXAM QUESTIONS WITH COMPLETE
SOLUTIONS
"The tendency to perceive a familiar object as having the same
brightness under different conditions of illumination" is the
definition of which of the following? Correct Answers
Brightness constancy
"Veiling reflections" are primarily a problem that occurs with
(a) computer screens and specular surfaces
(b) with "eggshell" paint surfaces
(c) roads that face due east or west
(d) people with retinal detachment Correct Answers computer
screens and specular surfaces
( 1 ) Which one of the following is not correct about solar
radiation? A) On June 21 there are 24 hours of sunlight north of
the Arctic Circle. B) About 70% of solar radiation is in the
visible part of the electromagnetic spectrum.
C) The Tropic of Cancer is at 23.5° north latitude.
D) Solar site evaluation tools predict the amount of solar access
at the point of measurement. Correct Answers About 70% of
solar radiation is in the visible part of the electromagnetic
spectrum
A "bearing angle" of 90° indicates that:
(a) the sun plane is perpendicular to the vertical surface in
question
(b) the sun plane is parallel to the vertical surface in question
(c) the sun is not falling on the vertical plane
,(d) the sun is below the horizon Correct Answers the sun plane
is parallel to the vertical surface in question
A diffuse surface will exhibit uniform brightness if the spacing
between light sources does not exceed approximately ___ times
their distance from the material.
(a) 1.5
b) 2
(c) 5
(d) 10 Correct Answers 1.5
A horizontal overhang can be made from an unbroken device
such as an awning or roof overhang, or it can be made of
horizontal louvers in a horizontal plane. These alternatives are
about equal in their ability to shade. Which one of the following
is not an advantage of using the horizontal louvers in a
horizontal plane?
A) Reduced wind load
C) Venting of hot air
B) Small scale elements and rich texture
D) Less maintenance Correct Answers Less maintenance
A large surface area to volume ratio would indicate what kind of
building?
A) envelope dominated
B) internally dominated
C) neither A nor B Correct Answers internally dominated
A luminaire was designed to have a candlepower distribution
curve that looks like a "batwing" because it would
A) minimize glare
,C) both A and B
B) minimize veiling reflections
D) neither A nor B Correct Answers both A and B
minimize glare & minimize veiling reflections
A spot light is used to illuminate a picture on a wall that is 3 feet
[1m] away. If the light is moved to a distance of 6 feet [2m], the
illumination on the picture will be _____ of what it was at 3 feet
[1m]?
A. 1/9
B. ¼
C. 1/3
D. ½ Correct Answers ¼
All of the following strategies can reduce the potential for glare,
except:
(a) splay the walls of an aperture
(b) locate windows to allow direct views outside
(c) provide daylight filters
(d) use walls adjacent to apertures are reflectors Correct
Answers locate windows to allow direct views outside
All of the following strategies can reduce the potential for glare,
except: Correct Answers locate windows to allow direct views
outside
At a solar altitude of 30 degrees, one can expect a daylight
illuminance of about 10,000 lux with no direct sun and ____
with direct sun.
(a) 10,000 lux
(b) 20,000 lux
, (c) 30,000 lux
(d) 40,000 lux Correct Answers 40,000 lux
At what time in the afternoon does the sun first hit the north wall
at latitude 36 on the 21st day of June?
A) 2:00
B) 2:30
C) 3:00
D) 3:30
E) 4:00 Correct Answers 3:30
Besides south facing glazing what else needs to be added to a
building to make passive solar really work in the winter? Hint: It
reduces the daily temperature swings. Correct Answers thermal
mass
Clerestories come in different forms. Name 3 types of top
lighting that are variations of the clerestory. Correct Answers
sawtooth, light scoop, monitor
Consider light shining on a window. As the "angle of incidence"
gets larger, the transmission of light gets ____?
A) smaller
B) larger
C) remains the same Correct Answers smaller
Daylight "profile A" demonstrates the light levels BLANK
adding the light shelf (see diagram below) Correct Answers
after
Daylight factor (DF) is defined as the ratio of ____.
SOLUTIONS
"The tendency to perceive a familiar object as having the same
brightness under different conditions of illumination" is the
definition of which of the following? Correct Answers
Brightness constancy
"Veiling reflections" are primarily a problem that occurs with
(a) computer screens and specular surfaces
(b) with "eggshell" paint surfaces
(c) roads that face due east or west
(d) people with retinal detachment Correct Answers computer
screens and specular surfaces
( 1 ) Which one of the following is not correct about solar
radiation? A) On June 21 there are 24 hours of sunlight north of
the Arctic Circle. B) About 70% of solar radiation is in the
visible part of the electromagnetic spectrum.
C) The Tropic of Cancer is at 23.5° north latitude.
D) Solar site evaluation tools predict the amount of solar access
at the point of measurement. Correct Answers About 70% of
solar radiation is in the visible part of the electromagnetic
spectrum
A "bearing angle" of 90° indicates that:
(a) the sun plane is perpendicular to the vertical surface in
question
(b) the sun plane is parallel to the vertical surface in question
(c) the sun is not falling on the vertical plane
,(d) the sun is below the horizon Correct Answers the sun plane
is parallel to the vertical surface in question
A diffuse surface will exhibit uniform brightness if the spacing
between light sources does not exceed approximately ___ times
their distance from the material.
(a) 1.5
b) 2
(c) 5
(d) 10 Correct Answers 1.5
A horizontal overhang can be made from an unbroken device
such as an awning or roof overhang, or it can be made of
horizontal louvers in a horizontal plane. These alternatives are
about equal in their ability to shade. Which one of the following
is not an advantage of using the horizontal louvers in a
horizontal plane?
A) Reduced wind load
C) Venting of hot air
B) Small scale elements and rich texture
D) Less maintenance Correct Answers Less maintenance
A large surface area to volume ratio would indicate what kind of
building?
A) envelope dominated
B) internally dominated
C) neither A nor B Correct Answers internally dominated
A luminaire was designed to have a candlepower distribution
curve that looks like a "batwing" because it would
A) minimize glare
,C) both A and B
B) minimize veiling reflections
D) neither A nor B Correct Answers both A and B
minimize glare & minimize veiling reflections
A spot light is used to illuminate a picture on a wall that is 3 feet
[1m] away. If the light is moved to a distance of 6 feet [2m], the
illumination on the picture will be _____ of what it was at 3 feet
[1m]?
A. 1/9
B. ¼
C. 1/3
D. ½ Correct Answers ¼
All of the following strategies can reduce the potential for glare,
except:
(a) splay the walls of an aperture
(b) locate windows to allow direct views outside
(c) provide daylight filters
(d) use walls adjacent to apertures are reflectors Correct
Answers locate windows to allow direct views outside
All of the following strategies can reduce the potential for glare,
except: Correct Answers locate windows to allow direct views
outside
At a solar altitude of 30 degrees, one can expect a daylight
illuminance of about 10,000 lux with no direct sun and ____
with direct sun.
(a) 10,000 lux
(b) 20,000 lux
, (c) 30,000 lux
(d) 40,000 lux Correct Answers 40,000 lux
At what time in the afternoon does the sun first hit the north wall
at latitude 36 on the 21st day of June?
A) 2:00
B) 2:30
C) 3:00
D) 3:30
E) 4:00 Correct Answers 3:30
Besides south facing glazing what else needs to be added to a
building to make passive solar really work in the winter? Hint: It
reduces the daily temperature swings. Correct Answers thermal
mass
Clerestories come in different forms. Name 3 types of top
lighting that are variations of the clerestory. Correct Answers
sawtooth, light scoop, monitor
Consider light shining on a window. As the "angle of incidence"
gets larger, the transmission of light gets ____?
A) smaller
B) larger
C) remains the same Correct Answers smaller
Daylight "profile A" demonstrates the light levels BLANK
adding the light shelf (see diagram below) Correct Answers
after
Daylight factor (DF) is defined as the ratio of ____.
