EXAM 3 PHYS 1149 ACTUAL QUESTIONS
100% VERIFIED 2025
How does the total amount of solar power incident on Earth compare with the power
consumption rate of our society? - CORRECT ANSWER>>>>Solar power is some
10,000 times current energy consumption rate
How long can the Solar power last? - CORRECT ANSWER>>>>10 billion years
What is a solar constant(S)? What is its value? Does it change with latitude or
longitude? - CORRECT ANSWER>>>>It's the same everywhere, the intensity of solar
radiation incident on Earth (S)
- does not change with latitude/longitude - it's constant
What is solar insolation? Does it change with latitude or longitude? - CORRECT
ANSWER>>>>Intensity of solar radiation projected onto the Earth's Surface
Incoming solar power per unit area on Earth's surface
Curvature of earth leads to change in insolation with latitude
Insolation changes with latitude
How does the global average solar insolation compare with the solar constant? -
CORRECT ANSWER>>>>1/4 of solar constant
What factors determine solar insolation? - CORRECT ANSWER>>>>Cloud cover,
atmospheric scattering lead to a time varying value for average insolation
What factors affect the solar insolation at a given geographical location? - CORRECT
ANSWER>>>>Cloud coverage, atmospheric composition
What is solar insolation under ideal lighting conditions? - CORRECT ANSWER>>>>100
W/m^2
What is the electromagnetic composition of solar energy reaching the upper
Atmosphere? - CORRECT ANSWER>>>>Total energy in solar radiation is distributed
non-uniformly across different electromagnetic waves
Information about how energy is distributed across the various wavelengths = spectrum
Solar spectrum is a blackbody spectrum corresponding to a blackbody temperature of
about 5800 K
Visible & Infrared (93%) UV (7%)
What is the difference between active solar heating and passive solar heating? -
CORRECT ANSWER>>>>-Active : use active to distribute
-Passive : distributed by itself
-Passive Solar Heating : avoids active devices (pumps or fans)
, Design modified to maximize solar energy input & distribute evenly throughout the
building
-Active Solar Heating : can provide space & heating & hot water - captures solar energy
with solar collectors & uses active devices to move energy
What are the four essential elements in the Passive Solar Heating Systems? -
CORRECT ANSWER>>>>1)Collection of Solar Energy through a large area of south
facing (in Northern Hemisphere) glass
2)High - R insulation prevents the collected solar thermal energy from escaping
3)A design to distribute the energy uniformly
4)Energy storage to compensate the predictable & unpredictable loss of solar radiation
(Collector, High - R Insulation, Design, and Energy Storage)
What should be the direction of facing of the collector window in a Passive Solar
Heating System if located in the Northern Hemisphere? - CORRECT
ANSWER>>>>Must be in Southern Hemisphere
What should be the direction of facing of the collector window in a Passive Solar
Heating System if located in the Southern Hemisphere? - CORRECT
ANSWER>>>>Must be in Northern Hemisphere
What are the essential elements of a Solar Thermal Power System? - CORRECT
ANSWER>>>>Solar Thermal Power and Photovoltaics
Solar Thermal Power System: Concentrator + Heat Engine + Generator
Solar Concentrators are characterized by their concentration ratio
What is concentration ratio? What kind of reflector has the best concentration ratio? -
CORRECT ANSWER>>>>Ratio of intensities of the concentrated sunlight to be
directed sunlight
Two axis concentrator (point focus)
What are the advantages and disadvantages of parabolic dish concentrators and
parabolic trough concentrators? - CORRECT ANSWER>>>>Two dimensional vs one
dimensions
What are Power Towers? What are Heliostats? - CORRECT ANSWER>>>>Tower has
the heat engine and flash sun-tracking mirrors
Power tower plants use a field of heliostats
Heliostats = flat sun tracking mirrors to focus sunlight on an object
Stream is generated either directly at the tower or using a heat transfer fluid
What is a semiconductor? Give an example. - CORRECT ANSWER>>>>Class of
materials with electrical properties between conductors and insulators
In metals charge carriers are free electrons
In semiconductors charge carriers are both electrons and holes
EX: Silicon and Geranium
100% VERIFIED 2025
How does the total amount of solar power incident on Earth compare with the power
consumption rate of our society? - CORRECT ANSWER>>>>Solar power is some
10,000 times current energy consumption rate
How long can the Solar power last? - CORRECT ANSWER>>>>10 billion years
What is a solar constant(S)? What is its value? Does it change with latitude or
longitude? - CORRECT ANSWER>>>>It's the same everywhere, the intensity of solar
radiation incident on Earth (S)
- does not change with latitude/longitude - it's constant
What is solar insolation? Does it change with latitude or longitude? - CORRECT
ANSWER>>>>Intensity of solar radiation projected onto the Earth's Surface
Incoming solar power per unit area on Earth's surface
Curvature of earth leads to change in insolation with latitude
Insolation changes with latitude
How does the global average solar insolation compare with the solar constant? -
CORRECT ANSWER>>>>1/4 of solar constant
What factors determine solar insolation? - CORRECT ANSWER>>>>Cloud cover,
atmospheric scattering lead to a time varying value for average insolation
What factors affect the solar insolation at a given geographical location? - CORRECT
ANSWER>>>>Cloud coverage, atmospheric composition
What is solar insolation under ideal lighting conditions? - CORRECT ANSWER>>>>100
W/m^2
What is the electromagnetic composition of solar energy reaching the upper
Atmosphere? - CORRECT ANSWER>>>>Total energy in solar radiation is distributed
non-uniformly across different electromagnetic waves
Information about how energy is distributed across the various wavelengths = spectrum
Solar spectrum is a blackbody spectrum corresponding to a blackbody temperature of
about 5800 K
Visible & Infrared (93%) UV (7%)
What is the difference between active solar heating and passive solar heating? -
CORRECT ANSWER>>>>-Active : use active to distribute
-Passive : distributed by itself
-Passive Solar Heating : avoids active devices (pumps or fans)
, Design modified to maximize solar energy input & distribute evenly throughout the
building
-Active Solar Heating : can provide space & heating & hot water - captures solar energy
with solar collectors & uses active devices to move energy
What are the four essential elements in the Passive Solar Heating Systems? -
CORRECT ANSWER>>>>1)Collection of Solar Energy through a large area of south
facing (in Northern Hemisphere) glass
2)High - R insulation prevents the collected solar thermal energy from escaping
3)A design to distribute the energy uniformly
4)Energy storage to compensate the predictable & unpredictable loss of solar radiation
(Collector, High - R Insulation, Design, and Energy Storage)
What should be the direction of facing of the collector window in a Passive Solar
Heating System if located in the Northern Hemisphere? - CORRECT
ANSWER>>>>Must be in Southern Hemisphere
What should be the direction of facing of the collector window in a Passive Solar
Heating System if located in the Southern Hemisphere? - CORRECT
ANSWER>>>>Must be in Northern Hemisphere
What are the essential elements of a Solar Thermal Power System? - CORRECT
ANSWER>>>>Solar Thermal Power and Photovoltaics
Solar Thermal Power System: Concentrator + Heat Engine + Generator
Solar Concentrators are characterized by their concentration ratio
What is concentration ratio? What kind of reflector has the best concentration ratio? -
CORRECT ANSWER>>>>Ratio of intensities of the concentrated sunlight to be
directed sunlight
Two axis concentrator (point focus)
What are the advantages and disadvantages of parabolic dish concentrators and
parabolic trough concentrators? - CORRECT ANSWER>>>>Two dimensional vs one
dimensions
What are Power Towers? What are Heliostats? - CORRECT ANSWER>>>>Tower has
the heat engine and flash sun-tracking mirrors
Power tower plants use a field of heliostats
Heliostats = flat sun tracking mirrors to focus sunlight on an object
Stream is generated either directly at the tower or using a heat transfer fluid
What is a semiconductor? Give an example. - CORRECT ANSWER>>>>Class of
materials with electrical properties between conductors and insulators
In metals charge carriers are free electrons
In semiconductors charge carriers are both electrons and holes
EX: Silicon and Geranium
