Q.1 What is the primary goal of a circular economy in the context of electronic waste?
Maximizing the lifespan of electronic components through reuse and recycling
Increasing the production of new electronic devices
Reducing the energy consumption of data centers
Eliminating all forms of electronic waste
Explanation - Circular economy aims to keep resources in use for as long as possible, extracting maximum value before recovery and regeneration, which is central to electronic waste management.
Correct answer is: Maximizing the lifespan of electronic components through reuse and recycling
Q.2 Which biotechnology process can be integrated with photovoltaic (PV) panels to enhance sustainability?
Algae-based biofuel production on panel surfaces
Using PV panels to power microbial fuel cells
Embedding genetically modified bacteria within solar cells
Applying anti‑reflective coatings derived from enzymes
Explanation - Power from PV panels can drive microbial fuel cells, linking renewable electricity with biotechnological wastewater treatment, supporting a circular approach.
Correct answer is: Using PV panels to power microbial fuel cells
Q.3 In sustainable environmental biotechnology, which term describes the conversion of organic waste into useful electricity?
Anaerobic digestion
Photolysis
Electroplating
Fermentation
Explanation - Anaerobic digestion breaks down organic matter in the absence of oxygen, producing biogas that can be used to generate electricity.
Correct answer is: Anaerobic digestion
Q.4 Which of the following is a key advantage of using bioelectrochemical systems (BES) for wastewater treatment?
Zero energy consumption
Simultaneous pollutant removal and electricity generation
Complete elimination of all contaminants
Requirement of high temperatures
Explanation - BES can treat wastewater while producing electricity, aligning with circular economy principles of resource recovery.
Correct answer is: Simultaneous pollutant removal and electricity generation
Q.5 What does the term "upcycling" refer to in the context of electronic components?
Converting waste electronics into higher‑value products
Breaking down electronics into raw materials
Disposing of electronics in landfills
Incinerating electronics for energy recovery
Explanation - Upcycling transforms waste into products of higher quality or value, a core concept of the circular economy.
Correct answer is: Converting waste electronics into higher‑value products
Q.6 Which of the following microbes is commonly used in microbial fuel cells to generate electricity from organic waste?
Escherichia coli
Shewanella oneidensis
Bacillus subtilis
Streptococcus pneumoniae
Explanation - Shewanella oneidensis transfers electrons to electrodes efficiently, making it a model organism for microbial fuel cells.
Correct answer is: Shewanella oneidensis
Q.7 In a life‑cycle assessment (LCA) of a renewable energy system, which stage typically has the highest environmental impact?
Manufacturing of components
Operation and maintenance
Decommissioning
Transportation of electricity
Explanation - Manufacturing, especially of rare‑earth metals and silicon, often contributes the most to the overall environmental burden.
Correct answer is: Manufacturing of components
Q.8 Which principle of the circular economy promotes designing products for easy disassembly?
Regeneration
Product as a Service
Design for Longevity
Design for Disassembly
Explanation - Design for Disassembly ensures components can be separated, repaired, or recycled efficiently, reducing waste.
Correct answer is: Design for Disassembly
Q.9 What is the main environmental benefit of using bioplastics derived from agricultural waste in electronic casings?
Higher electrical conductivity
Reduced carbon footprint compared to petroleum‑based plastics
Increased durability under high temperatures
Improved signal transmission
Explanation - Bioplastics from waste feedstocks lower greenhouse gas emissions and support waste valorization.
Correct answer is: Reduced carbon footprint compared to petroleum‑based plastics
Q.10 Which energy storage technology is most compatible with intermittent renewable sources and supports a circular economy by using recyclable materials?
Lead‑acid batteries
Lithium‑ion batteries with cobalt recycling
Nickel‑cadmium batteries
Flow batteries with vanadium recycling
Explanation - Flow batteries enable material recycling (e.g., vanadium) and can store large amounts of energy from variable renewable sources.
Correct answer is: Flow batteries with vanadium recycling
Q.11 Which of the following is a direct application of electrogenic bacteria in sustainable engineering?
Producing bio‑hydrogen through photosynthesis
Generating electricity from wastewater
Synthesizing biodegradable polymers
Removing heavy metals via biosorption
Explanation - Electrogenic bacteria transfer electrons to an electrode, turning organic waste into electricity.
Correct answer is: Generating electricity from wastewater
Q.12 In the context of sustainable electronics, what does the term "design for recycling" entail?
Using only biodegradable materials
Creating products that can be easily broken down into reusable components
Eliminating all metal components
Making devices waterproof
Explanation - Design for recycling focuses on material recovery by simplifying disassembly and using recyclable materials.
Correct answer is: Creating products that can be easily broken down into reusable components
Q.13 Which type of renewable energy conversion can be directly coupled with algal bioreactors to produce bio‑fuels?
Wind turbines
Solar photovoltaics
Hydropower
Geothermal energy
Explanation - Solar electricity can power lighting and pumps for algal bioreactors, enhancing biomass production for bio‑fuels.
Correct answer is: Solar photovoltaics
Q.14 What is the most significant challenge when integrating electronic waste recycling into a circular economy?
Lack of consumer interest
Complex material composition of devices
High cost of renewable energy
Insufficient landfill space
Explanation - Electronic devices contain many mixed materials that are difficult to separate and recycle efficiently.
Correct answer is: Complex material composition of devices
Q.15 Which of the following best describes a ‘product‑as‑a‑service’ (PaaS) model in a circular economy?
Selling a product with a lifetime warranty
Leasing equipment while retaining ownership and responsibility for end‑of‑life recovery
Providing free samples of a product
Offering discounted products for bulk purchases
Explanation - PaaS keeps manufacturers responsible for product lifecycle, encouraging reuse and recycling.
Correct answer is: Leasing equipment while retaining ownership and responsibility for end‑of‑life recovery
Q.16 Which process transforms lignocellulosic agricultural waste into bio‑electricity using engineered microbes?
Fermentation
Anaerobic digestion with genetically modified bacteria
Combustion
Photolysis
Explanation - Engineered microbes can enhance biogas production from lignocellulose, improving electricity generation efficiency.
Correct answer is: Anaerobic digestion with genetically modified bacteria
Q.17 In a sustainable power grid, what role does demand‑side management play?
Increasing generation capacity
Reducing consumer energy usage during peak times
Building more transmission lines
Storing excess renewable energy
Explanation - Demand‑side management shifts or reduces load to balance supply, enhancing grid stability and reducing waste.
Correct answer is: Reducing consumer energy usage during peak times
Q.18 Which indicator is most appropriate for measuring the circularity of an electronic product?
Carbon emission factor
Material circularity indicator (MCI)
Energy conversion efficiency
Operating voltage
Explanation - MCI quantifies the proportion of recycled or reused material in a product, reflecting circular performance.
Correct answer is: Material circularity indicator (MCI)
Q.19 What is the primary function of a biosensor integrated into a smart grid?
Detecting voltage fluctuations
Monitoring pollutant levels in the environment
Measuring current flow in transmission lines
Controlling the speed of turbines
Explanation - Biosensors can provide real‑time data on environmental contaminants, enabling adaptive grid management for sustainability.
Correct answer is: Monitoring pollutant levels in the environment
Q.20 Which of the following is NOT a benefit of using bio‑based conductive polymers in electronic devices?
Reduced reliance on fossil‑based polymers
Improved biodegradability
Higher thermal stability than metals
Potential for renewable sourcing
Explanation - Bio‑based conductive polymers generally have lower thermal stability compared to metals, limiting some high‑temperature applications.
Correct answer is: Higher thermal stability than metals
Q.21 In the context of sustainable electronic manufacturing, what does the term "closed‑loop supply chain" imply?
Materials flow only in one direction from supplier to consumer
All waste is sent to landfill after use
Materials are continuously reclaimed, refurbished, and reused within the system
Supply chain decisions are made without environmental considerations
Explanation - Closed‑loop supply chains keep materials in circulation, minimizing waste and supporting circularity.
Correct answer is: Materials are continuously reclaimed, refurbished, and reused within the system
Q.22 Which technology enables the recovery of rare earth elements (REEs) from spent electronic components?
Hydrometallurgical leaching
Mechanical shredding only
Combustion incineration
Physical compression
Explanation - Hydrometallurgical processes dissolve REEs from e‑waste, allowing their purification and reuse.
Correct answer is: Hydrometallurgical leaching
Q.23 What is the most common form of energy loss in power transmission that sustainable technologies aim to reduce?
Magnetic hysteresis
Resistive (I²R) losses
Radiative losses
Acoustic losses
Explanation - Resistive heating in conductors causes the largest losses; using superconductors or higher voltages can mitigate this.
Correct answer is: Resistive (I²R) losses
Q.24 Which of the following best describes the concept of "industrial symbiosis"?
Companies competing for the same resources
One industry’s waste becomes another industry’s raw material
Strict separation of industrial processes
Standardized production methods across all sectors
Explanation - Industrial symbiosis promotes resource efficiency by linking the waste streams of different industries.
Correct answer is: One industry’s waste becomes another industry’s raw material
Q.25 Which of the following renewable energy sources is most compatible with large‑scale biogas production?
Solar thermal
Wind power
Hydropower
Geothermal energy
Explanation - Wind power can provide electricity for pumps and mixers in anaerobic digesters, complementing biogas production.
Correct answer is: Wind power
Q.26 What is the main advantage of using a hybrid renewable‑microbial power system for remote off‑grid locations?
Eliminates the need for any maintenance
Provides continuous power by combining solar/wind with bio‑generation during low‑sun periods
Requires only fossil fuel backup
Reduces the size of the power system to a handheld device
Explanation - Hybrid systems balance intermittency, delivering reliable electricity in remote areas.
Correct answer is: Provides continuous power by combining solar/wind with bio‑generation during low‑sun periods
Q.27 Which metric is most useful for assessing the environmental impact of a bioprocess that produces electricity from wastewater?
Electrical conductivity of the water
Energy return on investment (EROI)
pH of the effluent
Voltage output per cell
Explanation - EROI compares the energy output to the energy input, indicating the efficiency and sustainability of the process.
Correct answer is: Energy return on investment (EROI)
Q.28 Which of the following is a major barrier to large‑scale adoption of microbial fuel cells (MFCs) in wastewater treatment plants?
Excessive heat generation
Low power density compared with conventional technologies
Inability to treat organic matter
Requirement for high‑pressure vessels
Explanation - Current MFCs generate relatively low power, limiting their competitiveness with established treatment methods.
Correct answer is: Low power density compared with conventional technologies
Q.29 What does the term "green electronics" primarily refer to?
Devices that run on solar power only
Electronics manufactured using environmentally friendly materials and processes
Gadgets with a green color casing
Electronic devices that consume no electricity
Explanation - Green electronics focus on reducing environmental impact across the product lifecycle, from material sourcing to end‑of‑life.
Correct answer is: Electronics manufactured using environmentally friendly materials and processes
Q.30 In a circular economy, which strategy best supports the concept of "regeneration"?
Landfilling all end‑of‑life products
Designing products to be disposable after a single use
Restoring natural systems through bio‑based product cycles
Increasing the use of single‑use plastics
Explanation - Regeneration emphasizes renewing ecosystems, often via bio‑based cycles that replenish resources.
Correct answer is: Restoring natural systems through bio‑based product cycles
Q.31 Which renewable energy technology can directly supply the electricity needed for an electrodialysis desalination plant?
Solar photovoltaics
Coal‑fired power plants
Nuclear reactors
Geothermal heat pumps
Explanation - PV systems can power the electric fields required for electrodialysis, enabling sustainable desalination.
Correct answer is: Solar photovoltaics
Q.32 What is a primary environmental advantage of using conductive bio‑films on electrode surfaces in bioelectrochemical systems?
Reduced need for metal electrodes
Higher temperatures can be tolerated
Increased mechanical strength
Enhanced electron transfer efficiency
Explanation - Conductive bio‑films facilitate rapid electron movement, improving power output and system efficiency.
Correct answer is: Enhanced electron transfer efficiency
Q.33 Which of the following best exemplifies a “resource‑efficient” approach in the design of electric vehicle (EV) batteries?
Using the highest possible amount of cobalt to increase energy density
Designing batteries for easy disassembly and material recovery
Increasing battery size to extend range
Integrating non‑recyclable plastics for structural support
Explanation - Resource‑efficient design enables recycling of valuable materials like lithium and cobalt, aligning with circular principles.
Correct answer is: Designing batteries for easy disassembly and material recovery
Q.34 Which of the following is a key factor influencing the biodegradability of a polymer used in electronic casings?
Electrical conductivity
Molecular weight and crystallinity
Color of the polymer
Magnetic permeability
Explanation - Lower molecular weight and less crystalline polymers degrade more readily in the environment.
Correct answer is: Molecular weight and crystallinity
Q.35 What does the term "energy harvesting" refer to in sustainable electronics?
Storing large amounts of energy in batteries
Capturing ambient energy (e.g., light, vibration) to power low‑power devices
Generating electricity from fossil fuels
Using nuclear energy for small gadgets
Explanation - Energy harvesting converts ambient sources into usable electricity, reducing dependence on external power supplies.
Correct answer is: Capturing ambient energy (e.g., light, vibration) to power low‑power devices
Q.36 Which of the following processes is most suitable for converting municipal solid waste into a usable fuel for power plants?
Mechanical recycling
Incineration with energy recovery
Landfilling
Composting
Explanation - Waste‑to‑energy incineration reduces waste volume while generating heat or electricity.
Correct answer is: Incineration with energy recovery
Q.37 In the context of a smart city, which technology helps optimize the use of renewable energy for electric vehicle charging stations?
Blockchain‑based energy trading platforms
Traditional SCADA systems
Manual metering
Fixed‑rate tariffs
Explanation - Blockchain can facilitate peer‑to‑peer energy exchange, allowing EV chargers to draw renewable energy when available.
Correct answer is: Blockchain‑based energy trading platforms
Q.38 Which of the following is an example of a "closed‑loop" water management system in a manufacturing plant?
Discharging treated wastewater into a river
Reusing cooling water after filtration and treatment within the plant
Using fresh water for each production batch
Storing wastewater in open ponds
Explanation - Closed‑loop water systems recycle water internally, reducing fresh water consumption and waste.
Correct answer is: Reusing cooling water after filtration and treatment within the plant
Q.39 Which factor most directly influences the power output of a microbial fuel cell?
pH of the anode chamber
Color of the electrode material
Ambient humidity
Length of the power cable
Explanation - Microbial activity and electron transfer are highly pH‑dependent; optimal pH maximizes power generation.
Correct answer is: pH of the anode chamber
Q.40 Which of the following is a benefit of using algae in biophotovoltaic devices?
Higher electrical conductivity than silicon
Direct conversion of sunlight to electricity through photosynthesis
Elimination of all moving parts
Instantaneous power generation without storage
Explanation - Algae can produce electrons during photosynthesis that are harvested in biophotovoltaic systems.
Correct answer is: Direct conversion of sunlight to electricity through photosynthesis
Q.41 What does the term "embodied energy" refer to in product life‑cycle analysis?
Energy stored in batteries
Total energy required to produce, transport, and dispose of a product
Energy lost as heat during operation
Energy used by a product during its use phase
Explanation - Embodied energy accounts for all energy inputs across a product’s life cycle, not just operational energy.
Correct answer is: Total energy required to produce, transport, and dispose of a product
Q.42 Which of the following best illustrates the concept of "upstream sustainability" in electronics manufacturing?
Recycling end‑of‑life devices
Choosing raw materials with low environmental impact
Designing products for easy repair
Implementing take‑back programs
Explanation - Upstream sustainability focuses on the early stages of the supply chain, such as raw material selection.
Correct answer is: Choosing raw materials with low environmental impact
Q.43 Which of the following renewable energy sources can be directly used to power a desalination process based on reverse osmosis?
Solar photovoltaic panels
Geothermal heat pumps
Wind turbines
All of the above
Explanation - PV, wind, and geothermal can all supply electricity for reverse‑osmosis desalination units.
Correct answer is: All of the above
Q.44 In a biorefinery concept, which product is typically co‑produced with bio‑electricity from lignocellulosic feedstock?
Synthetic polymers
Bio‑based chemicals such as succinic acid
Petroleum diesel
Aluminum alloys
Explanation - Biorefineries aim to generate multiple value‑added products, including chemicals, alongside energy.
Correct answer is: Bio‑based chemicals such as succinic acid
Q.45 Which technology enables the selective capture of CO₂ from industrial flue gases for use in microbial bioprocesses?
Membrane gas separation
Thermal cracking
Catalytic combustion
Electroplating
Explanation - Membrane systems can efficiently separate CO₂, which can then be fed to microalgae or engineered microbes.
Correct answer is: Membrane gas separation
Q.46 What is the main advantage of using a grid‑connected battery storage system with renewable generation for a campus sustainability project?
Eliminates the need for any renewable generation
Allows excess renewable energy to be stored and used during low‑generation periods
Guarantees 100% renewable electricity at all times
Reduces the total cost of renewable installation
Explanation - Battery storage balances supply and demand, enhancing the reliability of renewable energy.
Correct answer is: Allows excess renewable energy to be stored and used during low‑generation periods
Q.47 Which of the following is a key metric for evaluating the circularity of a battery recycling process?
Battery capacity (Ah)
Recovery rate of critical metals (e.g., lithium, cobalt)
Voltage of the recycled battery
Weight of the battery pack
Explanation - High recovery rates indicate efficient material reuse, a core circular economy goal.
Correct answer is: Recovery rate of critical metals (e.g., lithium, cobalt)
Q.48 Which of the following strategies can reduce the embodied carbon of a solar panel array?
Using thicker glass for durability
Choosing high‑purity silicon with lower energy manufacturing processes
Increasing the number of panels per megawatt
Adding more metal frames
Explanation - Lower‑energy manufacturing and high‑purity silicon reduce the carbon emissions associated with panel production.
Correct answer is: Choosing high‑purity silicon with lower energy manufacturing processes
Q.49 In a sustainable smart grid, what is the role of demand response programs?
Encouraging consumers to use more electricity during peak hours
Incentivizing users to shift or reduce electricity use during high‑price periods
Increasing the number of power plants
Providing free electricity to all consumers
Explanation - Demand response balances grid load by encouraging load shifting, improving efficiency and reducing emissions.
Correct answer is: Incentivizing users to shift or reduce electricity use during high‑price periods
Q.50 Which of the following is NOT a typical component of a bio‑based circular economy model for electronics?
Design for disassembly
Use of hazardous heavy metals
Material recovery loops
Renewable feedstocks
Explanation - Circular models aim to minimize hazardous substances to simplify recycling and reduce toxicity.
Correct answer is: Use of hazardous heavy metals
Q.51 Which process converts electrical energy into chemical energy stored in hydrogen, often paired with renewable electricity?
Electrolysis
Combustion
Fermentation
Distillation
Explanation - Electrolysis splits water into hydrogen and oxygen, storing renewable electricity in chemical form.
Correct answer is: Electrolysis
Q.52 What is the primary environmental benefit of integrating a biogas generator with a municipal wastewater treatment plant?
Reducing sludge volume and producing renewable electricity
Increasing the chemical oxygen demand (COD) of the effluent
Eliminating the need for any treatment processes
Providing a source of potable water
Explanation - Anaerobic digestion of sludge generates biogas for power while decreasing waste volume.
Correct answer is: Reducing sludge volume and producing renewable electricity
Q.53 Which of the following best describes the term "cradle‑to‑cradle" in product design?
Designing products that can be endlessly recycled or upcycled
Creating products with the longest possible lifespan
Ensuring products are cheap to manufacture
Focusing solely on the use phase of a product
Explanation - Cradle‑to‑cradle aims for perpetual material cycles, avoiding waste at any stage.
Correct answer is: Designing products that can be endlessly recycled or upcycled
Q.54 Which of the following renewable energy technologies typically requires the least land area per unit of electricity generated?
On‑shore wind farms
Solar photovoltaic farms
Hydropower dams
Geothermal power plants
Explanation - Geothermal installations have a high power density and occupy relatively small footprints.
Correct answer is: Geothermal power plants
Q.55 In the context of sustainable electronic waste management, what does the term "urban mining" refer to?
Extracting minerals from underground mines beneath cities
Recovering valuable metals and materials from discarded electronic devices
Mining for oil in metropolitan areas
Collecting rainwater for industrial use
Explanation - Urban mining taps into the resource pool hidden in e‑waste, reducing reliance on virgin mining.
Correct answer is: Recovering valuable metals and materials from discarded electronic devices
Q.56 Which of the following is a primary challenge when using algae for bio‑fuel production in a circular economy framework?
Low photosynthetic efficiency of algae
Excessive greenhouse gas emissions
Incompatibility with solar energy
Requirement for rare earth metals
Explanation - Algal bio‑fuel faces challenges in scaling due to limited photosynthetic yields and high cultivation costs.
Correct answer is: Low photosynthetic efficiency of algae
Q.57 Which of the following is an example of a “secondary raw material” in the context of electronic recycling?
Virgin copper mined from ore
Recovered copper from printed circuit boards
Aluminum extracted from bauxite
Silicon sourced from sand
Explanation - Secondary raw materials are reclaimed from waste streams, reducing demand for virgin extraction.
Correct answer is: Recovered copper from printed circuit boards
Q.58 What is the main purpose of implementing a “take‑back” scheme for consumer electronics?
To increase sales of new devices
To ensure proper collection and recycling of end‑of‑life products
To provide free accessories to consumers
To reduce manufacturing costs
Explanation - Take‑back programs facilitate responsible disposal and material recovery, supporting circularity.
Correct answer is: To ensure proper collection and recycling of end‑of‑life products
Q.59 Which of the following renewable energy storage methods involves converting electricity into a gaseous fuel?
Lithium‑ion batteries
Pumped hydro storage
Power‑to‑gas (hydrogen)
Flywheel energy storage
Explanation - Power‑to‑gas uses electrolysis to produce hydrogen, storing electricity as a gas.
Correct answer is: Power‑to‑gas (hydrogen)
Q.60 In a sustainable building, which technology can simultaneously provide lighting and generate electricity from indoor air microbes?
LED panels with built‑in solar cells
Microbial fuel cell integrated lighting
Fluorescent bulbs with algae culture
Incandescent lamps with bio‑catalysts
Explanation - MFCs can harvest electrons from indoor microbial activity to power low‑energy LED lights.
Correct answer is: Microbial fuel cell integrated lighting
Q.61 Which of the following is a major advantage of using a distributed renewable energy system over a centralized one?
Higher transmission losses
Improved resilience and reduced line losses
Greater dependence on fossil fuels
Increased need for large dams
Explanation - Distributed generation reduces transmission distance, enhancing reliability and efficiency.
Correct answer is: Improved resilience and reduced line losses
Q.62 What does the term "greenhouse gas intensity" of electricity refer to?
The total amount of electricity produced per year
The amount of CO₂ equivalent emitted per kilowatt‑hour generated
The number of greenhouse plants near power plants
The efficiency of solar panels
Explanation - GHG intensity measures emissions associated with electricity production, indicating its environmental impact.
Correct answer is: The amount of CO₂ equivalent emitted per kilowatt‑hour generated
Q.63 Which of the following best describes the role of a “circular supply chain” in electronics manufacturing?
A linear flow from raw material extraction to disposal
A system where materials are continuously reused, refurbished, or recycled
A supply chain that relies solely on imported components
A process that emphasizes rapid product obsolescence
Explanation - Circular supply chains aim to keep materials in use, reducing waste and resource extraction.
Correct answer is: A system where materials are continuously reused, refurbished, or recycled
Q.64 Which technology can convert low‑grade waste heat from industrial processes into electricity for use in a circular economy?
Thermoelectric generators (TEGs)
Wind turbines
Photovoltaic panels
Hydroelectric turbines
Explanation - TEGs directly convert temperature differences into electrical power, harvesting waste heat.
Correct answer is: Thermoelectric generators (TEGs)
Q.65 In the context of sustainable power electronics, which material is favored for its low environmental impact and recyclability?
Lead‑based solders
Tin‑silver‑copper (SAC) solder alloys
Mercury‑containing switches
Polyvinyl chloride (PVC) insulation
Explanation - SAC alloys avoid toxic lead and are easier to recycle, aligning with green electronics standards.
Correct answer is: Tin‑silver‑copper (SAC) solder alloys
Q.66 Which of the following is an example of a policy instrument that encourages circular economy practices in the electronics sector?
Subsidies for landfill expansion
Extended Producer Responsibility (EPR) regulations
Tax cuts for fossil fuel extraction
Increased import tariffs on recycled materials
Explanation - EPR holds manufacturers accountable for end‑of‑life product management, promoting recycling and design for circularity.
Correct answer is: Extended Producer Responsibility (EPR) regulations
Q.67 What is the main purpose of using a “life‑cycle thinking” approach when evaluating a new renewable energy technology?
To focus only on the operational phase
To consider environmental impacts from raw material extraction through disposal
To prioritize cost over environmental impact
To ignore the manufacturing stage
Explanation - Life‑cycle thinking assesses all stages, ensuring comprehensive sustainability evaluation.
Correct answer is: To consider environmental impacts from raw material extraction through disposal
Q.68 Which of the following processes can be used to convert organic municipal solid waste into a solid fuel for industrial use?
Gasification
Incineration with no energy recovery
Composting
Landfilling
Explanation - Gasification transforms waste into syngas and solid char, which can be used as a fuel.
Correct answer is: Gasification
Q.69 In the context of circular economy, what does the term "material loop closure" refer to?
Keeping materials in use by recycling and reusing them
Closing all factories at night
Using only renewable energy for production
Disposing of all waste in landfills
Explanation - Material loop closure aims to eliminate waste streams by continuously reusing materials.
Correct answer is: Keeping materials in use by recycling and reusing them
Q.70 Which of the following is a typical advantage of integrating Internet of Things (IoT) sensors in a smart water management system?
Increasing water consumption
Real‑time monitoring of leakages and consumption patterns
Making water treatment more costly
Eliminating the need for any human oversight
Explanation - IoT sensors enable early detection of leaks, improving water efficiency and conserving resources.
Correct answer is: Real‑time monitoring of leakages and consumption patterns
Q.71 Which renewable energy source is most commonly paired with algae bioreactors for CO₂ sequestration?
Solar photovoltaic electricity
Geothermal heat
Biomass combustion
Hydropower
Explanation - PV provides the electricity needed for lighting, pumps, and CO₂ enrichment in algae systems.
Correct answer is: Solar photovoltaic electricity
Q.72 What is the primary purpose of a “reverse logistics” system in a circular economy?
Optimizing the forward flow of goods from manufacturers to consumers
Managing the return flow of products for reuse, refurbishing, or recycling
Reducing the speed of product delivery
Increasing inventory levels at retail stores
Explanation - Reverse logistics handles product returns, facilitating material recovery and circularity.
Correct answer is: Managing the return flow of products for reuse, refurbishing, or recycling
Q.73 Which of the following is an emerging technology for recycling printed circuit boards (PCBs) that minimizes hazardous waste?
Mechanical shredding only
Hydrometallurgical leaching combined with bio‑leaching
Open‑air burning
Direct landfill disposal
Explanation - Combining chemical and biological leaching can recover metals while reducing toxic residues.
Correct answer is: Hydrometallurgical leaching combined with bio‑leaching
Q.74 Which factor most directly determines the feasibility of a micro‑grid powered entirely by renewable sources in a remote community?
Average annual wind speed and solar irradiance
Number of households with smartphones
Distance to the nearest highway
Local cuisine preferences
Explanation - Renewable resource availability dictates the potential for self‑sufficient micro‑grids.
Correct answer is: Average annual wind speed and solar irradiance
Q.75 What is a key environmental benefit of using bio‑based solvents in the manufacturing of electronic components?
Higher electrical conductivity
Reduced volatile organic compound (VOC) emissions
Increased device weight
Improved magnetic properties
Explanation - Bio‑based solvents are often less toxic and emit fewer VOCs, improving manufacturing sustainability.
Correct answer is: Reduced volatile organic compound (VOC) emissions
Q.76 Which of the following is an example of a closed‑loop system for heat recovery in an industrial plant?
Using waste heat to pre‑heat incoming raw materials
Ventilating waste heat directly to the atmosphere
Increasing cooling water flow without reuse
Discharging hot effluent into a river
Explanation - Recovering waste heat for pre‑heating reduces external energy demand and enhances efficiency.
Correct answer is: Using waste heat to pre‑heat incoming raw materials
Q.77 Which of the following best illustrates the concept of "energy‑positive" buildings?
Buildings that consume more energy than they generate
Buildings that generate more renewable energy than they consume over a year
Buildings that use only fossil fuels for heating
Buildings with no insulation
Explanation - Energy‑positive buildings produce a net surplus of clean energy, supporting sustainability goals.
Correct answer is: Buildings that generate more renewable energy than they consume over a year
Q.78 In a circular economy for electronics, what is the purpose of "design for remanufacturing"?
To make products harder to disassemble
To enable products to be restored to 'like‑new' condition after use
To increase the number of disposable components
To discourage repair and reuse
Explanation - Design for remanufacturing ensures that used products can be efficiently refurbished and re‑entered into the market.
Correct answer is: To enable products to be restored to 'like‑new' condition after use
Q.79 Which of the following technologies is most suitable for converting surplus solar electricity into a storable chemical fuel?
Lithium‑ion battery storage
Power‑to‑gas (hydrogen) via electrolysis
Direct current transmission
Capacitor banks
Explanation - Power‑to‑gas stores electricity as hydrogen, a chemical fuel that can be stored long‑term.
Correct answer is: Power‑to‑gas (hydrogen) via electrolysis
Q.80 Which of the following is a key metric for evaluating the sustainability of a bio‑electrochemical system used for wastewater treatment?
Chemical Oxygen Demand (COD) removal efficiency
Color of the anode
Length of the power cable
Number of LEDs in the control panel
Explanation - COD removal indicates how effectively the system cleans wastewater while generating electricity.
Correct answer is: Chemical Oxygen Demand (COD) removal efficiency
Q.81 Which of the following strategies can reduce the environmental impact of rare‑earth element (REE) extraction for use in high‑performance magnets?
Increasing the depth of mining operations
Developing recycling processes for REEs from end‑of‑life products
Replacing REEs with lead in all applications
Using larger quantities of REEs in new devices
Explanation - Recycling REEs lessens the need for new mining, mitigating environmental damage.
Correct answer is: Developing recycling processes for REEs from end‑of‑life products
Q.82 What is the main purpose of a “smart inverter” in a renewable energy system?
To store electricity as heat
To convert DC to AC while providing grid support functions
To increase the weight of the system
To reduce the voltage of the output
Explanation - Smart inverters not only convert power but also enable grid stabilization, frequency regulation, and communication.
Correct answer is: To convert DC to AC while providing grid support functions
Q.83 Which of the following is a primary reason for incorporating life‑cycle thinking into the design of electric vehicle batteries?
To increase the vehicle's top speed
To minimize resource use, improve recyclability, and reduce environmental impact
To make the battery heavier
To ensure the battery never degrades
Explanation - Life‑cycle thinking guides choices that reduce material demand and enable end‑of‑life recovery.
Correct answer is: To minimize resource use, improve recyclability, and reduce environmental impact
Q.84 Which of the following is an example of a “biogenic” waste that can be valorized in a circular economy?
Plastic packaging
Food‑processing residues
Glass bottles
Aluminum cans
Explanation - Biogenic waste originates from biological sources and can be transformed into bio‑fuels or chemicals.
Correct answer is: Food‑processing residues
Q.85 What does the term "energy‑water nexus" describe?
The relationship between energy production and water consumption
The amount of water needed to cool electric cars
The use of water as a battery electrolyte
The generation of electricity from rainwater
Explanation - The energy‑water nexus highlights the interdependence of energy and water resources, crucial for sustainable planning.
Correct answer is: The relationship between energy production and water consumption
Q.86 Which of the following best describes the concept of “industrial ecology”?
Isolating each industry to prevent cross‑contamination
Mimicking natural ecosystems where waste from one industry becomes input for another
Increasing the number of factories in a region
Focusing solely on agricultural productivity
Explanation - Industrial ecology aims to create synergistic loops between industries, reducing overall waste.
Correct answer is: Mimicking natural ecosystems where waste from one industry becomes input for another
Q.87 Which of the following renewable technologies is most suitable for providing baseload power in a circular economy framework?
Solar photovoltaics without storage
Wind turbines with battery storage
Geothermal power plants
Run‑of‑the‑river hydroelectric plants
Explanation - Geothermal provides continuous, reliable power irrespective of weather, supporting baseload needs.
Correct answer is: Geothermal power plants
Q.88 What is the primary advantage of using a “bio‑based epoxy resin” in printed circuit board (PCB) manufacturing?
Higher electrical resistance
Reduced reliance on petroleum‑derived chemicals and improved end‑of‑life recyclability
Increased heat resistance above 500 °C
Improved magnetic shielding
Explanation - Bio‑based resins lower fossil fuel use and can be more easily recycled, aligning with circular principles.
Correct answer is: Reduced reliance on petroleum‑derived chemicals and improved end‑of‑life recyclability
Q.89 Which of the following is a key characteristic of a “smart city” that supports sustainable environmental biotechnology?
Extensive use of single‑use plastics
Integration of sensor networks for real‑time monitoring of air and water quality
Unlimited expansion of urban sprawl
Reliance on coal‑fired power plants
Explanation - Smart sensors enable rapid detection and response to environmental issues, facilitating biotechnological interventions.
Correct answer is: Integration of sensor networks for real‑time monitoring of air and water quality
Q.90 Which of the following processes is most effective for removing nitrogen from wastewater while generating electricity?
Anammox (anaerobic ammonium oxidation) coupled with a microbial fuel cell
Chemical precipitation with lime
Physical filtration through sand
Ultraviolet disinfection
Explanation - Anammox removes nitrogen anaerobically and can be integrated with MFCs to produce electricity.
Correct answer is: Anammox (anaerobic ammonium oxidation) coupled with a microbial fuel cell
Q.91 What is the main purpose of a “material passport” in a circular economy for electronic devices?
To provide a travel document for the device
To document the composition, origin, and recyclability of materials in a product
To increase the cost of the product
To certify the device as waterproof
Explanation - Material passports improve transparency, aiding recycling and responsible sourcing.
Correct answer is: To document the composition, origin, and recyclability of materials in a product
Q.92 Which of the following is an emerging method for recovering lithium from spent batteries that aligns with circular economy goals?
High‑temperature smelting
Hydrometallurgical leaching combined with bio‑leaching using bacteria
Open‑air burning
Disposal in municipal landfills
Explanation - Combining chemical leaching with bio‑leaching reduces harsh chemicals and improves metal recovery rates.
Correct answer is: Hydrometallurgical leaching combined with bio‑leaching using bacteria
Q.93 Which of the following best describes the concept of "energy justice" in the transition to sustainable electricity systems?
Ensuring only wealthy regions receive renewable energy
Providing equitable access to clean, affordable, and reliable energy for all communities
Prioritizing energy production over environmental concerns
Focusing solely on technological advancements
Explanation - Energy justice emphasizes fairness in energy access, pricing, and participation in decision‑making.
Correct answer is: Providing equitable access to clean, affordable, and reliable energy for all communities
Q.94 Which of the following is a major benefit of integrating solar‑driven electrolysis with a hydrogen fuel cell for backup power in remote off‑grid sites?
Eliminating the need for any water source
Providing long‑duration, zero‑emission backup power using locally generated hydrogen
Increasing carbon emissions during operation
Requiring continuous fossil fuel input
Explanation - Solar‑driven electrolysis creates hydrogen on‑site, which fuel cells can later use for clean power.
Correct answer is: Providing long‑duration, zero‑emission backup power using locally generated hydrogen
Q.95 What does the term "zero‑waste manufacturing" aim to achieve?
Producing goods without any waste streams, by reusing all outputs in other processes
Eliminating all product designs
Increasing the amount of waste sent to landfills
Using only metal components
Explanation - Zero‑waste manufacturing seeks to close material loops so that no waste leaves the facility.
Correct answer is: Producing goods without any waste streams, by reusing all outputs in other processes
Q.96 Which of the following renewable energy technologies can be directly coupled with a microbial electrosynthesis system to produce value‑added chemicals?
Solar photovoltaic panels
Wind turbines
Hydroelectric turbines
All of the above
Explanation - Any renewable electricity source can power microbial electrosynthesis, converting CO₂ into chemicals.
Correct answer is: All of the above