Questions & Answers
Browse all 25 questions from the
Fundamentals of Renewable Energy Science study set below.
Each question shows the correct answer — select a study format above to practice interactively.
1
What is the primary physical process that converts sunlight directly into electricity in a photovoltaic cell?
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A
The thermal expansion effect
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B
The photoelectric effect
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C
The piezoelectric effect
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D
The thermionic emission effect
2
Which component in a wind turbine is responsible for converting the rotational mechanical energy into electrical energy?
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A
Gearbox
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B
Generator
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C
Anemometer
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D
Nacelle
3
In geothermal energy systems, what is the primary medium typically used to transport heat from the Earth's crust to the surface?
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A
Molten iron
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B
Water or steam
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C
Natural gas
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D
Liquid nitrogen
4
What is the maximum theoretical efficiency limit of a wind turbine, known as the Betz Limit?
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A
59.3%
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B
75.0%
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C
42.5%
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D
33.3%
5
Which type of solar technology uses mirrors to concentrate sunlight onto a receiver to produce high-temperature heat?
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A
Photovoltaic cells
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B
Concentrated Solar Power (CSP)
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C
Solar thermal panels
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D
Passive solar design
6
In a hydroelectric power plant, what determines the maximum potential energy of the water stored in a reservoir?
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A
The flow rate only
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B
The head height and water mass
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C
The salinity of the water
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D
The water temperature
7
What is the main chemical component of biogas produced by the anaerobic digestion of organic matter?
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A
Methane
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B
Hydrogen sulfide
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C
Oxygen
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D
Carbon monoxide
8
Which gas is commonly used as a storage medium for hydrogen fuel cells due to its high energy density per unit mass?
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A
Helium
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B
Neon
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C
Hydrogen
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D
Argon
9
What is the term for the ratio of the actual energy output of a power plant over a period of time to the theoretical maximum output?
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A
Capacity factor
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B
Efficiency ratio
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C
Load demand
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D
Energy density
10
Which law of thermodynamics dictates that energy cannot be created or destroyed, only transformed?
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A
First Law
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B
Second Law
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C
Third Law
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D
Zeroth Law
11
What type of ocean energy relies on the gravitational pull of the moon and sun?
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A
Wave energy
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B
Tidal energy
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C
Ocean thermal energy conversion
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D
Salinity gradient energy
12
Which semiconductor material is most commonly used in the manufacturing of commercial solar photovoltaic cells?
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A
Gallium arsenide
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B
Silicon
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C
Cadmium telluride
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D
Copper indium gallium selenide
13
What is the primary purpose of an inverter in a solar energy system?
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A
To increase voltage
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B
To store electricity
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C
To convert DC to AC electricity
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D
To track the sun's movement
14
In a pumped-storage hydroelectric plant, what is the function of the secondary reservoir?
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A
To filter the water
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B
To provide a place to store water during low electricity demand
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C
To increase the water temperature
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D
To act as a backup for tidal flow
15
Which layer of the Earth is the primary heat source for geothermal energy?
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A
The crust
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B
The inner core
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C
The mantle
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D
The atmosphere
16
What defines 'base load' power in an energy grid?
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A
The minimum level of demand on an electrical grid over 24 hours
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B
The maximum demand reached during peak summer
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C
The energy provided only by fossil fuels
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D
The total capacity of all connected wind turbines
17
What is the effect of increased temperature on the efficiency of a typical silicon solar cell?
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A
Efficiency increases
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B
Efficiency decreases
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C
Efficiency remains constant
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D
Efficiency becomes zero
18
Which substance is removed from flue gases in biomass plants to mitigate acid rain?
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A
Nitrogen oxides
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B
Sulfur dioxide
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C
Noble gases
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D
Water vapor
19
What is the primary mechanism that generates electricity in ocean thermal energy conversion (OTEC)?
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A
Tidal currents
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B
Temperature difference between deep and surface water
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C
Wave height
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D
Marine biomass
20
What is the main advantage of using a variable-speed drive in wind turbine operations?
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A
It stops the turbine in high winds
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B
It optimizes aerodynamic efficiency across different wind speeds
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C
It eliminates the need for a gearbox
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D
It prevents the nacelle from rotating
21
Which of the following is considered a 'dispatchable' renewable energy source?
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A
Solar PV
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B
Wind power
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C
Biomass
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D
Run-of-river hydro
22
What is the purpose of 'feed-in tariffs' in renewable energy policy?
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A
To tax fossil fuels
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B
To provide long-term contracts for renewable energy producers
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C
To limit the size of solar panels
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D
To control the price of residential electricity
23
Which physical property of hydrogen makes it difficult to store and transport compared to natural gas?
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A
Low atomic mass
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B
High boiling point
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C
Low volumetric energy density
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D
High reactivity with steel
24
What is the 'band gap' in the context of photovoltaic materials?
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A
The energy required to move an electron from the valence band to the conduction band
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B
The thickness of the silicon wafer
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C
The distance between two solar panels
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D
The speed of light through the cell
25
Which process converts biomass into liquid fuel such as ethanol?
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A
Combustion
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B
Fermentation
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C
Pyrolysis
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D
Gasification
