Category: Renewable Energy Objective Questions

Solar Energy Interview Questions on “Empirical Equations for Estimating Solar Radiation Availability on Horizontal Surface for Cloudy Skies”.

1. What is the relationship between insolation and cloud cover in sky?
a) Inverse
b) Directly proportional
c) Square
d) Exponential

Answer: a
Clarification: From ancient time, people knew the relationship between sunshine and cloud cover. There is an inverse relationship between insolation and the amount of sky covered by clouds.

2. Which of the following is a reason for inverse relationship between insolation and cloud cover in sky?
a) Sunshine duration records are caused by sun being obstructed by transparent cloud cover
b) Sunshine duration records are caused by sun being obstructed by opaque cloud cover
c) Sunshine duration records are caused by sunshine being transmitted through opaque cloud cover
d) Sunshine duration records are caused by sun being obstructed by cloud cover

Answer: b
Clarification: There is an inverse relationship between insolation and cloud cover in sky. This is because of sunshine duration records are caused by sun being obstructed by transparent cloud cover.

3. Which does Angstrom-Savinov formula tell?
a) Relationship between local solar radiation and global cloudiness
b) Relationship between local solar radiation and local cloudiness
c) Relationship between global solar radiation and mean cloudiness
d) Relationship between global solar radiation and global cloudiness

Answer: c
Clarification: Angstrom-Savinov formula is a relationship between global solar radiation (H) and mean cloudiness (C). It is given by mathematical relationship, H=H₀[1−(1−k)C].

4. What does the constant “k” signify in the Angstrom-Savinov formula?
a) Global solar radiation
b) Mean cloudiness
c) Reflection of solar radiation within clouds
d) Transmission of solar radiation within clouds

Answer: d
Clarification: The constant “k” signifies the transmission of solar radiation within clouds. It is defined to account for the partial and practical transmission of solar radiation through clouds.

5. The constant “k” in Angstrom-Savinov formula depends on ________
a) latitude of the location
b) longitude of the location
c) solar radiation
d) cloud opacity

Answer: a
Clarification: The constant “k” accounts for transmission of solar radiation through clouds. It depends on the latitude of the location. It does not depend on the solar radiation and cloud capacity.

6. How does the constant “k” in Angstrom-Savinov vary in high and low latitudes?
a) Between 0.55 in high latitudes and 0.22 in low latitudes
b) Between 0.55 in high latitudes and 0.33 in low latitudes
c) Between 0.33 in high latitudes and 0.55 in low latitudes
d) Between 0 in high latitudes and 0.9 in low latitudes

Answer: b
Clarification: The constant “k” in Angstrom-Savinov has a range from 0.33 to 0.55. It varies between 0.55 in high latitudes and 0.33 in low latitudes.

7. Which of the following models uses linear regression to estimate solar radiation from sunshine duration?
a) Angstrom-Savinov
b) Ertekin and Yladtz
c) Anstrom-Prescott
d) Sen

Answer: c
Clarification: Anstrom-Prescott model uses linear regression to estimate solar radiation from sunshine duration. H/H₀=a+b*(S/S₀) is the regression equation. H is global radiation and S is the sunshine duration.

8. Akinoglu and Fcevit uses a _______ to estimate solar radiation.
a) linear model
b) power model
c) exponential model
d) quadratic model

Answer: d
Clarification: Akinoglu and Fcevit uses a quadratic model to estimate solar radiation. Like Angstom-Savinov, it also estimates solar radiation from sunshine duration.

9. How is an empirical model developed?
a) From data acquired via sensors or measuring instruments
b) From theoretical analysis
c) From deep learning
d) From trial and error

Answer: a
Clarification: Empirical models of any system is developed from data acquired via sensors or measuring instruments. The developers decide the variables and the output and perform various numerical analysis to formulate a relationship.

10. What does the ratio of global solar radiation (H) and estimated daily global radiation for cloudless sky (H₀) indicate?
a) Solar radiation transmission ratio
b) Clearness index
c) Solar radiation reflection percentage
d) Turbidity

Answer: b
Clarification: The ratio of global solar radiation (H) and estimated daily global radiation for cloudless sky (H₀) indicates clearness index. It neither indicates solar radiation transmission ratio nor does it indicate turbidity. Solar radiation reflection percentage is indicated by albedo.

11. Which of the following is important during data acquisition from measuring instruments? Assume that details about data to be collected is known.
a) Type of data
b) Materials used to manufacture measuring instruments
c) Location, environment and characteristics of measuring instrument
d) Brand of measuring instruments

Answer: c
Clarification: Assuming that details about the data to be collected is known, location, environment and characteristics of measuring instrument is important. This is because instruments can give different values under different conditions. Basically, data acquisition procedure should be consistent and authentic.

12. Which of the following statistical indicator is used to evaluate any type of model?
a) mean
b) median
c) error
d) root mean square error

Answer: d
Clarification: Root mean square error is a commonly used statistical indicator to evaluate any type of model. It basically describes the mean error between simulated/measured/observed values and the true values.

13. Why do ground-based observers overestimate overcast cloud cover?
a) Clouds appear to fill large area of sky when near horizon
b) Clouds appear to fill large area of sky when far from horizon
c) Clouds appear to fill small area of sky when near horizon
d) Clouds appear to fill small area of sky when far from horizon

Answer: a
Clarification: Ground-based observers tend to overestimate overcast cloud covers. This is because clouds with vertical extents appear to fill a greater area of sky when located near the horizon than when they are overhead.

14. Reduction of error between simulated values and the true values increases accuracy of the empirical model.
a) True
b) False

Answer: a
Clarification: Reduction of error between simulated values and the true values increases accuracy of the empirical model. This is because decrement in error indicates that simulated values are moving closer to true/desired values.

15. Cloud cover estimation is free from error.
a) True
b) False

Answer: b
Clarification: Like any other estimation, cloud cover estimation is not free from errors. For instance, a small hole in the cloud could remain open for a long period of time thereby allowing more sunlight to pass through than estimated.

Wind Energy Multiple Choice Questions on “Origin of Winds – 1”.

1. Which of the following provides energy for winds to blow naturally?
a) Sun
b) Water
c) Man
d) Food

Answer: a
Clarification: The energy that drives winds originates from the sun’s heat received along with sunlight. The heat creates areas of low pressure and high pressure, thereby causing winds to blow. Wind is abiotic and does not need food. Any wind blowing due to man is artificial. Water aids in magnifying a low or high pressure area but does not cause winds.

2. Wind flows from _______ pressure area to ________ pressure area.
a) high, high
b) high, low
c) low, high
d) low, low

Answer: b
Clarification: Wind always flows from a high pressure area to a low pressure area. The difference in pressures causes wind to flow from in a direction. Winds originate from the heat received by sun which heat’s the earth’s surface unevenly resulting in a pressure difference.

3. What is a gust?
a) No change in wind speed
b) A brief decrease in wind speed for a very long period of time
c) A brief increase in wind speed for a very short period of time
d) A brief increase in wind speed for a very long period of time

Answer: c
Clarification: A gust or a wind gust is a brief increase in wind speed for a very short period of time, typically less than 20 seconds and has a transient characteristic unlike a squall.

4. What is a squall?
a) A sudden, sharp increase in wind speed lasting for a few hours
b) A sudden, sharp decrease in wind speed lasting for a few minutes
c) A sudden, sharp decrease in wind speed lasting for a few hours
d) A sudden, sharp increase in wind speed lasting for a few minutes

Answer: d
Clarification: A squall is a sudden, sharp increase in wind speed lasting for a few minutes. Squalls occur during rain showers, thunderstorms or heavy snow fall.

5. A windstorm _______
a) is strong enough to cause property damage
b) is not stronger than gust
c) does not exist
d) is not strong enough to cause property damage

Answer: a
Clarification: A windstorm consists of winds strong enough to cause property damage like uprooting of trees and damaging erected buildings. Wind speed in a typical windstorm exceeds 55km/s and can be extremely detrimental.

6. What are planetary or prevailing winds?
a) Winds not blowing from one latitude to another
b) Winds blowing from one latitude to another
c) Gusts
d) Winds that do not cover large areas of earth

Answer: b
Clarification: Planetary winds are winds that blow from one latitude to another throughout the year due to latitudinal differences in air pressure. They cover large areas of earth.

7. Which of the following are the two most important planetary winds?
a) Hosting
b) Trades and economics
c) Trade winds and westerly winds
d) Deployment

Answer: c
Clarification: Trade winds and westerly winds are the two most important planetary or prevailing winds. Other options – trade and economics, hosting and deployment are not related to winds.

8. What are trade winds?
a) Winds blowing from equatorial low pressure areas to sub-tropical high pressure areas
b) Winds that trade with each other
c) Winds blowing from equatorial high pressure areas to sub-tropical low pressure areas
d) Winds blowing from sub-tropical high pressure areas to equatorial low pressure areas

Answer: d
Clarification: Trade winds are extremely steady winds blowing from sub-tropical high pressure areas to equatorial low pressure areas. They maintain a constant direction throughout their course.

9. How does Coriolis effect trade winds in Northern Hemisphere?
a) Coriolis effect deflects trade winds to the right
b) Coriolis effect deflects trade winds to the left
c) Coriolis effect does not affect the trade winds in Northern Hemisphere
d) Coriolis effect only affects the trade winds in Southern Hemisphere

Answer: a
Clarification: Coriolis effect and Ferrel’s law disrupt the flow of trade winds from north to south and deflect them towards right in the Northern Hemisphere. Thus, they blow in a north east direction in the Northern Hemisphere.

10. How does Coriolis effect trade winds in Southern Hemisphere?
a) Coriolis effect deflects trade winds to the right
b) Coriolis effect deflects trade winds to the left
c) Coriolis effect does not affect the trade winds in Southern Hemisphere
d) Coriolis effect only affects the trade winds in Northern Hemisphere

Answer: b
Clarification: Coriolis effect and Ferrel’s law disrupt the flow of trade winds flowing from north to south and deflect them towards left in the Southern Hemisphere. Thus, they blow in a south east direction in the Southern Hemisphere.

11. Trade winds ______
a) do not maintain a constant direction but blow steadily
b) maintain a constant direction but do not blow steadily
c) maintain a constant direction and blow steadily
d) shrinking technique

Answer: c
Clarification: Trade winds are also called as tropical easterlies. They maintain the same direction and blow steadily in that direction. Shrinking technique is not related to winds.

Biomass Energy Multiple Choice Questions on “Photosynthesis Process”.

1. What is photosynthesis?
a) Plants generating carbohydrates and oxygen from carbon dioxide, water and sunlight using chlorophyll
b) Algae generating carbohydrates and oxygen from carbon dioxide, water and sunlight using chlorophyll
c) Cyanobacteria generating carbohydrates and oxygen from carbon dioxide, water and sunlight using chlorophyll
d) Photoautotroph generating carbohydrates and oxygen from carbon dioxide, water and sunlight

Answer: d
Clarification: Photosynthesis is the process by which photoautotrophs generate food for themselves. They use carbon dioxide, water and sunlight to generate carbohydrates and oxygen. Photo means light.

2. What is the primary product of photosynthesis?
a) Glucose
b) Oxygen
c) Water
d) Carbon dioxide

Answer: a
Clarification: The primary product of photosynthesis is glucose. Oxygen is the by product. Water and carbon dioxide are the reactants.

3. Which of the following best indicates photosynthesis?
a) Carbon dioxide + water → oxygen + glucose
b) 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂ (in the presence of sunlight)
c) Carbon dioxide + water → glucose + oxygen (in the presence of sunlight)
d) Oxygen + glucose → carbon dioxide + water

Answer: b
Clarification: Photosynthesis occurs in the presence of sunlight. The balanced reaction of photosynthesis best describes the process of photosynthesis. The option with oxygen and glucose as reactants is not photosynthesis.

4. Which of the following organisms can perform photosynthesis?
a) Autotrophs
b) Algae
c) Photoautotrophs
d) Plants

Answer: c
Clarification: Photoautotrophs are organisms that perform photosynthesis to produce food for themselves. Algae and plants come under the category of photoautotrophs. All autotrophs are not necessarily photoautotrophs.

5. Which of the following are photoautotrophs?
a) Cyanobacteria, algae, plants
b) Archaebacteria
c) Deer
d) Tiger

Answer: a
Clarification: Cyanobacteria, algae and plants are photoautotrophs. Archaebacteria are chemoautotrophs. Deer and tiger are not autotrophs as they do not create their own food.

6. Conversion of usable sunlight energy into chemical energy is associated with _______
a) Red pigmentation
b) Green pigmentation
c) Orange pigmentation
d) Fruits

Answer: b
Clarification: Conversion of usable sunlight energy into chemical energy is associated with green pigmentation. This green pigmentation is called chlorophyll. Plants and algae consist of chlorophyll which is a key ingredient for photosynthesis.

7. Cyanobacteria have chloroplasts.
a) True
b) False

Answer: b
Clarification: Though cyanobacteria are photoautotrophs, they do not have chloroplasts. Instead, the chlorophyll is stored in thylakoids in their cytoplasm.

8. _______ and _______ is present in all chlorophylls.
a) A hydrophilic tail, a lipid soluble head
b) A hydrophobic tail, a lipid soluble head
c) A hydrophilic tail, a lipid insoluble head
d) A lipid soluble tail, a hydrophilic head

Answer: d
Clarification: A lipid soluble tail and a hydrophilic head is present in all chlorophylls. The tail is a lipid soluble hydrocarbon and the hydrophilic head consists of magnesium ion at its centre.

9. What type of chemical reactions are involved in photosynthesis?
a) Condensation reactions and redox reactions
b) Combustion
c) Double displacement
d) Single displacement

Answer: a
Clarification: The chemical reactions involved in photosynthesis are condensation reactions and redox reactions respectively. Combustion, single and double displacement reactions do not occur in photosynthesis.

10. What is the condensation reaction responsible for in the process of photosynthesis?
a) Electron transfer
b) Splitting out water molecules
c) Splitting out water molecules and phosphorylation
d) Electron transfer and phosphorylation

Answer: c
Clarification: Condensation reaction is responsible for splitting out water molecules and phosphorylation. Phosphorylation is the addition of a phosphate group to an organic compound. Electron transfer occurs in a redox reaction.

11. Where does the light-dependent reactions in the process of photosynthesis occur?
a) Stroma of chloroplasts
b) Thylakoid of chloroplasts
c) Inner membranes
d) Grana of chloroplasts

Answer: d
Clarification: The light-dependent reactions in the process of photosynthesis occur in the grana of chloroplasts. These reactions require the light energy to make energy-carrier molecules that are used further.

12. Where does the light-independent reactions in the process of photosynthesis occur?
a) Stroma of chloroplasts
b) Thylakoid of chloroplasts
c) Outer membranes
d) Grana of chloroplasts

Answer: a
Clarification: The light-independent reactions in the process of photosynthesis occur in the stroma of chloroplasts. The products of light reaction are used to make carbohydrates from carbon dioxide.

13. What is photoionisation? Assume presence of sunlight.
a) Freeing of electron from the molecule to form a negatively charged chlorophyll ion
b) Freeing of photoexcited electron from the molecule to form a positively charged chlorophyll ion
c) Absorbing of electron from the molecule to form a negatively charged chlorophyll ion
d) Absorbing of electron from the molecule to form a positively charged chlorophyll ion

Answer: b
Clarification: Electrons of chlorophyll molecule gain energy and move to higher energy level when light is absorbed. On gaining sufficiently high energy, the electron leaves the molecule thereby forming a positively charged chlorophyll ion. This process is called photoionisation.

14. Where does the energy to drive the electron transfer system come from?
a) Photosystem 1
b) Photosystem 3 and photosystem 2
c) Photosystem 1 and photosystem 2
d) Photosystem 1 and photosystem 3

Answer: c
Clarification: An electron transfer system (basically, a series of chemical reactions) carries two electrons to and fro across the thylakoid membrane. The energy for the system comes from photosystem 1 and photosystem 2.

15. Which of the following are products of light-dependent reactions?
a) ATP and glyceraldehyde 3-phosphate
b) Glyceraldehyde 3-phosphate and NADPH
c) Carbohydrates
d) ATP and NADPH

Answer: c
Clarification: The light-dependent reactions require direct energy of sunlight. They are a series of chemical reactions forming ATP and NADPH. These products are further used by light-independent reactions to produce carbohydrates.

Ocean Energy online quiz on “Tidal Energy – 2”.

1. What is a tidal lagoon?
a) A man-made structure that spans the area of coastline with a high tidal range
b) A man-made structure that spans the entire coastline
c) A barrage
d) A fast-flowing water body caused due to tides

Answer: a
Clarification: A tidal lagoon spans that area of coastline which has a high tidal range. The large volume of water is collected in a man-made structure for electricity generation. Tidal stream is a fast-flowing water body caused due to tides.

2. How does a tidal lagoon work?
a) By storing sea water
b) By creating a difference in water levels
c) By placing the turbine in the running water
d) By creating barrages

Answer: b
Clarification: Tidal lagoon works by creating a difference in water levels. The water on the higher level is passed through a turbine to generate electricity. Tidal barrages work by creating barrages.

3. Which of the following steps best describes the working of tidal lagoons?
a) Floods → generator turbines → turbine wicket gates → lagoon → difference in water level between lagoon and sea
b) Floods → turbine wicket gates → generator turbines → lagoon → difference in water level between lagoon and sea
c) Floods → turbine wicket gates → lagoon → difference in water level between lagoon and sea → generator turbines
d) Turbine wicket gates → floods → lagoon → difference in water level between lagoon and sea → generator turbines

Answer: c
Clarification: Sea water flows into lagoons which are controlled by turbine wicket gates. These gates control the flow and can be completely closed to stop the water from entering the lagoon. Once the difference in the water level between lagoon and sea is optimized, the gates are opened thereby allowing water to flow through generator turbines.

4. Tidal lagoon is _______
a) unidirectional
b) unpredictable
c) the same as tidal stream
d) bi-directional

Answer: d
Clarification: Tidal lagoon is bi-directional. This is because the difference in water level between the lagoon and sea can be created by both, the incoming tides and the outgoing (ebbing) tides.

5. Tidal power is renewable because _________
a) tide falls and rises without fuel
b) tide falls and rises with fuel
c) tide neither falls nor rises without fuel
d) tide neither falls nor rises with fuel

Answer: a
Clarification: The tidal power is renewable because the tides fall and rise without any external fuel. This is caused by the gravitational forces of moon and earth’s rotation.

6. How many high tides occur every day?
a) One
b) Two
c) Four
d) Three

Answer: b
Clarification: Two high tides occur each day. This is because the earth rotates through two tidal bulges every lunar day. When the earth is in one of the bulges, coastal areas experience a high tide.

7. How many low tides occur every day?
a) One
b) Five
c) Two
d) Four

Answer: c
Clarification: Two low tides occur each day. This is because the earth rotates through two tidal bulges every lunar day. When the earth is not in one of the bulges, a low tide occurs.

8. On which two sides of the earth do the tidal forces cause water to bulge out?
a) Both sides closest to moon
b) Both sides farthest from moon
c) Both sides facing the sun
d) Side closest to the moon and farthest from the moon

Answer: d
Clarification: Tides are caused by the gravitational forces of moon acting on earth. Side closes to the moon and sides farthest from the moon bulge out due to these tidal forces.

9. Bulges of water are called high tides.
a) True
b) False

Answer: a
Clarification: Bulges of water are called high tides. The two earth’s sides namely, the one closest to the moon and the one farthest from the moon experience these bulges – high tides.

10. What is a tide mill?
a) A dam to store the tide
b) A water mill driven by tidal rise and fall
c) A barrage
d) A lagoon

Answer: b
Clarification: A tide mill is a water mill driven by tidal rise and fall. A dam is created across a tidal inlet to store the water thereby acting as a reservoir. A tidal mill is not same as a dam.

11. How does a tide mill work?
a) By storing the water and creating a difference in water level
b) By storing the water when the tide is low and releasing it through a turbine when the tide is high
c) By storing the water when the tide is high and releasing it through a turbine when the tide is low
d) By using the running water of a tide

Answer: c
Clarification: The tide mill works by storing the water when the tide is high and releasing it through a turbine when the tide is low. The water is stored in a dam constructed across a suitable tidal inlet.

12. Which of the following is similar to the working of tidal stream generator?
a) Geothermal turbine
b) Heat pump
c) Anaerobic digestion
d) Wind turbine

Answer: d
Clarification: The working of tidal stream generator is similar to that of a wind turbine. Both use the kinetic energy of the respective fluids to rotate the turbine and generate electricity. Anaerobic digestion is a technique to treat and harness energy from biomass. It does not used turbines. Geothermal turbine and heat pumps use the thermal energy of the fluids.

13. Both horizontal and vertical turbines are used to harness energy from tides.
a) True
b) False

Answer: a
Clarification: Depending on the tidal stream various turbines are used to harness the kinetic energy of the incoming tide. Some of the commonly used turbines are horizontal, vertical, open and ducted.

14. What is dynamic tidal power?
a) A theoretical technology exploiting potential energy of tides
b) A theoretical technology exploiting potential and kinetic energy of tides
c) A practical technology exploiting kinetic and potential energy of tides
d) A practical technology exploiting thermal energy of tides

Answer: b
Clarification: Dynamic tidal power is a theoretical technology that exploits an interaction between the potential and kinetic energy of tides. It proposes the construction of long dams from coast into the sea so as to introduce tidal phase differences. These phase differences result in a differential water-level.

15. Strong coast-parallel oscillating tidal currents are found in ______
a) India
b) United States
c) China
d) Australia

Answer: c
Clarification: Strong coast-parallel oscillating tidal currents are generally found in China, UK and Korea. Dynamic tidal power (DTP) is a theoretical technology that features such currents and proposes harvesting energy from such currents.

Renewable Energy Multiple Choice Questions on “Environment-Economy-Energy and Sustainable Development”.

1. What is “3E”?
a) Energy, economy and environment
b) Reduce, reuse and recycle
c) Energy, economy and envision
d) Ergonomics, evolution and economy
Answer: a
Clarification: “3E” is a nomenclature used for energy, economy and environment. It describes the interrelation between them. “3Rs” are used for reduce, reuse and recycle.

2. Which of the following is the 7^th goal of the eight millennium goals of United Nations?
a) To eradicate extreme poverty and hunger
b) To ensure environment sustainability
c) To reduce child mortality
d) To develop a global partnership for development
Answer: b
Clarification: The seventh goal of the eight millennium development goals of UN is to ensure environment sustainability. The first is to eradicate extreme poverty and hunger. The fourth is to reduce child mortality and the eight is to develop a global partnership for development.

3. Which of the following is relates the three elements of “3E”?
a) Energy from fossil fuels
b) Energy from natural gas
c) Renewable energy sources and technology
d) Economy
Answer: c
Clarification: Renewable energy sources and their respective technologies relate the three elements of “3E”. This is because the renewable technology incorporates an environment-centered strategy thereby forcing the economy to adopt it as well.

4. Which of the following ensures sustainable growth?
a) Positive economic growth, deterioration of environment with economic expansion and energy resource meeting energy demands
b) Negative economic growth, deterioration of environment with economic expansion and energy resource meeting energy demands
c) Positive economic growth, non-deterioration of environment with economic expansion and growth of energy resource not meeting energy demands
d) Positive economic growth, deterioration of environment with economic expansion and growth of energy resource meeting energy demands
Answer: d
Clarification: It is necessary that the environment does not deteriorate with economic expansion for sustainable growth. Also, positive economic growth and growth of energy resource meeting energy demands are key elements of sustainable growth.

5. Sustainable development requires that energy resource ________
a) cannot be exhausted completely
b) can be complete exhausted
c) can destroy the environment
d) cannot meet the growing demand
Answer: a
Clarification: Sustainable development requires that energy resource cannot be exhausted completely. If any one resource is at the brink of exhaustion, it has to be substituted by another or a shift to another source has to be made.

6. Which of the following contributes towards growth of economic and energy?
a) Intermittent capital and human resource investment
b) Continuous capital and human resource investment
c) Decrement in capital and human resource investment
d) No capital and human resource investment
Answer: b
Clarification: Continuous capital and human resource investment contributes towards the growth of economy and energy. Continuous investments lead to inventions and innovations which can disrupt the economy and make pervasive changes.

7. Which of the following energy resources seems inexhaustible?
a) Natural gas
b) Coal
c) Sun
d) Petrol
Answer: c
Clarification: Sun seems an inexhaustible source of energy. Coal, natural gas and petrol are fossil fuels which are already being consumed at an alarming rate.

8. For sustainable development, environment damage rate _____ environment recovery rate.
a) should be greater than the
b) should be exponentially greater than the
c) should be same as the
d) should be lesser than the
Answer: d
Clarification: For sustainable development, environment damage rate should be less than environment recovery rate. If it is greater even by a small margin, the system cannot sustain itself due to positive feedback.

9. Which of the following best describes the aim of sustainable consumption and production?
a) To reduce resource consumption, waste generation and emissions across the full life cycle of processes and products
b) To increase resource consumption, waste generation and emissions across the full life cycle of processes and products
c) To reduce resource consumption, increase waste generation and emissions across the full life cycle of processes and products
d) To increase resource consumption, reduce waste generation and emissions across the full life cycle of processes and products
Answer: a
Clarification: Sustainable consumption and production aims to reduce resource consumption. It also aims to reduce waste generation and emissions across the full life cycle of processes and products.

10. Which of the following best describes green economy?
a) A high carbon, resource inefficient and socially inclusive economy
b) A low carbon, resource efficient and socially inclusive economy
c) A low carbon, resource inefficient and socially exclusive economy
d) A high carbon, resource efficient and socially inclusive economy
Answer: b
Clarification: A green economy is a low carbon, resource efficient and socially inclusive economy. Without the society being consciously involved, the green economy cannot be created let alone sustain.

11. What is the goal of sustainability in any process?
a) To maintain the process finitely
b) To eventually eliminate the process
c) To maintain the process indefinitely
d) To support damaging the environment
Answer: c
Clarification: The goal of sustainability is to maintain the process indefinitely without endangering natural biotic system. Damaging the environment or anything else at the cost of maintaining the process goes against the definition.

12. What are the three pillars of sustainable development?
a) Energy, economy and ergonomics
b) Environment, economy and evolution
c) Energy and evolution
d) Energy, economy and environment.
Answer: d
Clarification: The three pillars of sustainable development are energy, economy and environment. Ergonomics is the scientific study of understanding human interactions with other elements of a system.

13. What is the main problem with development of countries?
a) Strain on environment to absorb the damage and self-heal
b) Decrement in poverty
c) Higher energy consumption per capita
d) Lower energy consumption per capita
Answer: a
Clarification: The main problem with development of countries is the strain it puts on the environment to absorb the damage. It also unarguably assumes that the environment will heat by itself without any cost. Decrement in poverty and high energy consumption per capita are the consequences of development.

14. Sustainable development binds together the concern for natural systems with social and political challenges.
a) True
b) False
Answer: a
Clarification: Sustainable development binds together the concern for natural systems with social, economic and political challenges faced by humans. Ideally, the society grows without destroying the environment. It might even treat the damage that has already been done.

15. Sustainability can be achieved by replacing existing resources with other resources of equal value.
a) True
b) False
Answer: a
Clarification: Sustainability can be achieved by replacing existing resources with other resources of equal value or of greater value. However, it should be noted that the replacement or operation of these new resources does not degrade the environment.

Solar Energy Questions and Answers for Experienced people on “Hourly Global, Diffuse and Beam Radiations on Horizontal
Surface Under Cloudless Skies”.

1. Hourly radiation values can be used to evaluate the performance of ________
a) flat plate collectors
b) curved collectors
c) parabolic collectors
d) metallic collectors
Answer: a
Clarification: Hourly values of solar radiation provides very precise information about performance of solar energy systems. For example, hourly radiation values can be used to evaluate the performance of flat plate collectors.

2. Why are global and diffuse radiation values not measured?
a) Because of sophisticated measuring instruments
b) Because measuring instruments are not available everywhere
c) Because of unavailability of skilled labour to operate measuring instruments
d) Because measuring instruments are not available everywhere
Answer: b
Clarification: Global and diffuse radiation values are not measured mainly because measuring instruments are not available at all locations, in every lab or institute. The major problem is not unavailability of funds or skilled labour.

3. Which of the following is generally used to compute global and diffuse radiation values?
a) Parabolic dish
b) Flat plate collector
c) Theoretical models
d) Pyranometer
Answer: c
Clarification: Global and diffuse radiation values are generally computed from theoretical models. This is because of unavailability of measuring instruments at all locations. Pyranometer is used wherever and whenever possible.

4. Which of the following can be used to estimate beam radiation?
a) Photoelectric effect
b) Solar insolation constant
c) Time taken by sun’s rays to reach earth
d) Zenith angle and altitude
Answer: d
Clarification: Zenith angle and altitude of the location can be used to estimate beam radiation transmitted through a clear atmosphere. Though solar insolation constant is used, it is either just a scaling factor or a constant and not a variable. Photoelectric effect is not related to beam radiation.

5. What is zenith angle?
a) Angle between sun and vertical
b) Angle between the line joining the location on earth’s surface and the equatorial plane
c) Angle between extended sun’s rays to earth’s center and equatorial plane
d) Angle between projection of sun’s rays on horizontal surface and equatorial plane
Answer: a
Clarification: Zenith angle is the angle between sun’s ray and the vertical. Latitude is angle between the line joining the location on earth’s surface and the equatorial plane. Sun’s declination angle is angle between extended sun’s rays to earth’s center and equatorial plane.

6. Which of the following is not used to calculate hourly radiation?
a) Sun’s declination angle
b) Material of parabolic dish
c) Solar constant
d) Hour angle
Answer: b
Clarification: Material of the collector is not used to calculate hourly radiation. The material of the collector affects the values being measured and not theoretically computed values. Sun’s declination, hour angle and solar constant play their part in the computation.

7. Solar radiation on a horizontal surface is the summation of _______
a) direct and active solar radiation
b) active and diffuse solar radiation
c) diffuse and direct solar radiation
d) electrons and photons
Answer: c
Clarification: Solar radiation on a horizontal surface is the summation of diffuse and direct solar radiation. It is not just a summation of electrons and photons as the option does not specify the source of electrons and photons.

8. What are the two models used to determine diffuse radiation?
a) Rayleigh scattering and Hybrid pi model
b) Parametric model and Rayleigh scattering
c) Decomposition model and Hybrid pi model
d) Parametric and decomposition models
Answer: d
Clarification: The two models used to determine diffuse radiation are parametric and decomposition models. Rayleigh scattering is the scattering of light by suspended particles in a medium. Hybrid pi model is used to model a transistor and is not related to radiation.

9. Which of the following is required as a parameter in a parametric model?
a) Cloud cover
b) Solar insolation constant
c) Material of measuring instrument
d) Type of measuring instrument
Answer: a
Clarification: Cloud cover, atmospheric turbidity, fractional sunshine and perceptible water content are necessities of a parametric model. Though solar insolation constant may be required, it is not a parameter. In any theoretical mode, material and type of measuring instrument is irrelevant.

10. Which of the following is an example of parametric model used to compute diffuse radiation?
a) Chandrasekaran and Kumar’s model
b) ASHRAE model
c) Erb’s model
d) T-model
Answer: b
Clarification: ASHRAE model is an example of parametric model used to compute diffuse radiation. Erb’s model and Chandrasekaran and Kumar’s model are not parametric models. T-model is used to model a transistor and is not related to radiation.

11. How do decomposition models compute diffuse solar radiation?
a) From specific information of environmental conditions
b) From measuring instruments
c) From global solar radiation data
d) From ASHRAE model
Answer: c
Clarification: Decomposition models use global solar radiation data to estimate and compute diffuse solar radiation. Parametric models require specific information of environmental conditions to compute diffuse solar radiation.

12. Decomposition models are based on correlation between ____________
a) global solar radiation and active radiation
b) diffuse and UV radiation on vertical surface
c) diffuse and total radiation on inclined surface
d) diffuse and total radiation on horizontal surface
Answer: d
Clarification: Decomposition models are based on correlation between diffuse and total radiation on horizontal surface. UV radiation is a part of the total received solar radiation.

13. Which of the following does the correlation of decomposition models (between diffuse and total radiation on horizontal surface) depend on?
a) Hourly clearness index ratio
b) Daily clearness index ratio
c) Hourly global horizontal radiation
d) Yearly extraterrestrial radiation
Answer: a
Clarification: The correlation of decomposition models (between diffuse and total radiation on horizontal surface) depend on hourly clearness index ratio. It is the ratio of hourly global horizontal radiation to hourly extraterrestrial radiation.

14. The clearness index is a measure of atmospheric effects in an isolated place.
a) True
b) False
Answer: b
Clarification: The clearness index is a measure of atmospheric effects in an isolated place. It is used by decomposition models to estimate diffuse solar radiation data from global solar radiation.

15. Nijegorodov’s model revised the constants of ASHRAE’s model.
a) True
b) False
Answer: a
Clarification: Nijegorodov’s model revised the constants of ASHRAE’s model using a computer program. It was used to predict hourly and daily global solar radiation in Botswana.

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