SOLAR ENERGY EXAM WITH 100%
CORRECT ANSWERS
What is a Tokamak? - Answer- A device that uses strong magnetic fields to contain and
heat nuclei with the goal of inducing sustained fusion
When will we have commercially economic controlled nuclear fusion reactors? -
Answer- unanswered definitively
What fuel did the Three Mile Island nuclear plant use? - Answer- Low-Enriched Uranium
(LEU)
About what % of the USA's total electrical power come from nuclear plants? - Answer-
20%
About what % of the USA's total power needs are satisfied by nuclear plants? - Answer-
20%
About how long does it take for unprocessed high level waste from a current-day
nuclear reactor to decrease in radioactivity to the level of natural uranium ore? -
Answer- 10,000 to 100,000 years
About how long is it projected for high-level waste from a liquid salt thorium reactor to
decrease in radioactivity to the level of natural uranium ore? - Answer- 300-500 years
What is the major reason that the US doesn't process spent nuclear fuel (high-level
waste) from nuclear reactors? - Answer- very expensive.
what is joule - Answer- SI unit of energy
The large hyperbolic shaped structures at many nuclear power plants are? - Answer-
cooling towers
Where was there a major nuclear reactor accident in 1979? - Answer- Three Mile
Island, Pennsylvania, USA
The atomic bomb that was dropped on Hiroshima, Japan, used what fissionable
isotope? - Answer- U-235
, If you could convert 1.0 kg of matter completely into energy using E = mc2 how much
energy could be produced? - Answer- E=(1kg)(3.0×108m/s)2=9×1016J
In a heat engine, that is the relationship between the hot reservoir and the cold
reservoir? - Answer- Efficiency depends on the temperature difference
Which machines have a type of heat engine? - Answer- Cars (internal combustion
engines)
Steam turbines (power plants)
Jet engines
Refrigerators and air conditioners (heat pump cycle is reversed heat engine
What is 0°C in Kelvin? - Answer- 273K
Burning methane as CH4 + 2O2 à CO2 + 2H2O, how many molecules of methane are
consumed per molecule of CO2 produced? - Answer- 1 molecule of CH4 produces 1
molecule of CO2
Ratio: 1:1
What is typical human body temperature in Kelvin? - Answer- 310K
The efficiency of a modern coal-burning electric plant might be about? - Answer- 33-
40%
The theoretical maximum efficiency of an engine operating at 1273 Kelvin with a
radiator at 300 Kelvin is? - Answer- ηmax=1−ThTc=1−300\ 1273≈0.765≈76.5%
Which is a cold reservoir for the Three Mile Island nuclear power plant? - Answer- The
nearby river or cooling water that absorbs excess heat from the reactor
star - Answer- a very large spherical body of hydrogen and helium plasmas and gases
held together by its own gravity and emitting radiation due to the release of energy by
nuclear fusion reactions in its interior
how can we observe the sun - Answer- at a wavelength s throughout the
electromagnetic spectrum
what type of radiation does the sun emits - Answer- visible 47% and infrared 51%
radiation
coronal holes - Answer- region of low density of sun where solar wind flows from
outward pressure - Answer- from heat caused by nuclear reactions.
balances out the inward gravitational pull toward the suns center
produces a static condition called hydrostatic equilibrium.
CORRECT ANSWERS
What is a Tokamak? - Answer- A device that uses strong magnetic fields to contain and
heat nuclei with the goal of inducing sustained fusion
When will we have commercially economic controlled nuclear fusion reactors? -
Answer- unanswered definitively
What fuel did the Three Mile Island nuclear plant use? - Answer- Low-Enriched Uranium
(LEU)
About what % of the USA's total electrical power come from nuclear plants? - Answer-
20%
About what % of the USA's total power needs are satisfied by nuclear plants? - Answer-
20%
About how long does it take for unprocessed high level waste from a current-day
nuclear reactor to decrease in radioactivity to the level of natural uranium ore? -
Answer- 10,000 to 100,000 years
About how long is it projected for high-level waste from a liquid salt thorium reactor to
decrease in radioactivity to the level of natural uranium ore? - Answer- 300-500 years
What is the major reason that the US doesn't process spent nuclear fuel (high-level
waste) from nuclear reactors? - Answer- very expensive.
what is joule - Answer- SI unit of energy
The large hyperbolic shaped structures at many nuclear power plants are? - Answer-
cooling towers
Where was there a major nuclear reactor accident in 1979? - Answer- Three Mile
Island, Pennsylvania, USA
The atomic bomb that was dropped on Hiroshima, Japan, used what fissionable
isotope? - Answer- U-235
, If you could convert 1.0 kg of matter completely into energy using E = mc2 how much
energy could be produced? - Answer- E=(1kg)(3.0×108m/s)2=9×1016J
In a heat engine, that is the relationship between the hot reservoir and the cold
reservoir? - Answer- Efficiency depends on the temperature difference
Which machines have a type of heat engine? - Answer- Cars (internal combustion
engines)
Steam turbines (power plants)
Jet engines
Refrigerators and air conditioners (heat pump cycle is reversed heat engine
What is 0°C in Kelvin? - Answer- 273K
Burning methane as CH4 + 2O2 à CO2 + 2H2O, how many molecules of methane are
consumed per molecule of CO2 produced? - Answer- 1 molecule of CH4 produces 1
molecule of CO2
Ratio: 1:1
What is typical human body temperature in Kelvin? - Answer- 310K
The efficiency of a modern coal-burning electric plant might be about? - Answer- 33-
40%
The theoretical maximum efficiency of an engine operating at 1273 Kelvin with a
radiator at 300 Kelvin is? - Answer- ηmax=1−ThTc=1−300\ 1273≈0.765≈76.5%
Which is a cold reservoir for the Three Mile Island nuclear power plant? - Answer- The
nearby river or cooling water that absorbs excess heat from the reactor
star - Answer- a very large spherical body of hydrogen and helium plasmas and gases
held together by its own gravity and emitting radiation due to the release of energy by
nuclear fusion reactions in its interior
how can we observe the sun - Answer- at a wavelength s throughout the
electromagnetic spectrum
what type of radiation does the sun emits - Answer- visible 47% and infrared 51%
radiation
coronal holes - Answer- region of low density of sun where solar wind flows from
outward pressure - Answer- from heat caused by nuclear reactions.
balances out the inward gravitational pull toward the suns center
produces a static condition called hydrostatic equilibrium.
