UGC NET Questions (Paper – 1)

Statements A and B are correct because they reflect the accepted waste management hierarchy that favours prevention, reduction, reuse and recycling over final disposal. Modern sustainable waste policies prioritise minimising waste generation and recovering resources before considering landfilling or incineration. Statements C and D are incorrect as open dumping is environmentally unsound and energy recovery processes can generate emissions and require careful control. Therefore, the combination with A and B only is the correct answer.

Option A:
Option A is correct because it accurately lists the two statements that correspond to the widely accepted principles of the waste hierarchy. It notes that prevention and reduction should come first and that recycling and reuse are preferable to landfilling. Since it excludes the clearly incorrect statements C and D, this combination fully matches the requirement.

Option B:
Option B is incorrect because it adds statement C, which wrongly describes open dumping as an environmentally sound and endorsed practice. In reality, open dumping leads to leachate formation, odour, vector breeding and air pollution. Including such a false statement makes the entire option invalid.

Option C:
Option C is incorrect because it groups B, C and D, and both C and D are wrong. While B is correct, C wrongly promotes open dumping and D wrongly claims that energy recovery is always benign and emission-free. The presence of two incorrect statements means this combination cannot be accepted.

Option D:
Option D is incorrect because it declares all four statements A, B, C and D to be correct. Although A and B are correct, C and D are false and contradict principles of environmentally sound waste management. As a result, selecting all four statements is inconsistent with the conceptual framework of the unit.

Composting uses microorganisms to break down organic waste such as food scraps, garden trimmings and farm residues. Under controlled moisture, temperature and aeration, this biological process converts waste into a stable, humus-like product that can be applied to soil as manure. It reduces the amount of biodegradable material going to landfills and recycles nutrients back into the ecosystem. Therefore, describing composting as controlled biological decomposition of organic waste is accurate.

Option A:
Option A is incorrect because shredding plastics is a physical pre-treatment for recycling, not a biological transformation. Plastics do not decompose in normal composting systems and require different handling methods.

Option B:
Option B is correct as it specifies both the biological nature of the process and the beneficial end product. Properly managed composting can also reduce pathogens and odours, making it a sustainable option for organic waste management.

Option C:
Option C is incorrect since incineration involves burning waste to reduce volume and possibly recover energy. While it can treat mixed waste, it does not produce manure and has different environmental implications, including air emissions.

Option D:
Option D is incorrect because landfilling hazardous waste is a containment strategy for dangerous materials. Composting, in contrast, is intended for biodegradable organic matter and is not an appropriate method for hazardous chemicals.

The 3R principle is a hierarchy that guides waste management towards sustainability. The most preferred option is to reduce waste generation at source, followed by reusing products to extend their life, and finally recycling materials so they can be processed into new products. This order minimises resource use and environmental impact. Hence, the correct sequence is Reduce, Reuse, Recycle, as given in option C.

Option A:
Option A is incorrect because it starts with reuse and places reduction later. While reuse is beneficial, preventing waste generation in the first place through reduction is considered even more desirable.

Option B:
Option B is incorrect since it begins with recycling, which, although useful, still requires energy and processing. Waste reduction and reuse are higher priorities as they avoid or delay waste creation.

Option C:
Option C is correct because it follows the established waste management hierarchy: first reduce consumption and waste, then reuse products, and finally recycle materials. This sequence aligns with environmental guidelines and UGC NET content.

Option D:
Option D is incorrect as it reverses the preferred order and again starts with recycling. Such a sequence does not reflect the principle of preventing and minimising waste before managing it.

Water reuse means employing treated wastewater as a resource for beneficial uses,instead of discharging it directly into the environment. This reduces freshwater demand and pollution simultaneously. The stem describes using treated wastewater for irrigation or landscaping,which is a classic case of water reuse. Hence Option C is correct.

Option A:
Depletion refers to reducing the stock of a resource irreversibly. Using treated wastewater does not deplete water but actually conserves freshwater,so Option A is wrong.

Option B:
Mining water would imply extracting water from deep or fossil sources. It does not describe circulation of treated wastewater back into productive uses.

Option C:
Reuse involves giving water a second life in new applications after adequate treatment. It aligns perfectly with the practice highlighted in the question stem.

Option D:
Withdrawal refers to taking water from a natural source like a river or aquifer. The question focuses on using already collected and treated wastewater,so Option D is not appropriate.

Electronic waste refers specifically to discarded electrical and electronic equipment and their parts. Such waste often contains hazardous substances like heavy metals and brominated flame retardants. Improper handling can lead to serious environmental and health problems. Therefore the description in the question clearly fits electronic waste.

Option A:
Biomedical waste consists of materials generated from diagnosis,treatment and research activities in healthcare institutions. It includes contaminated dressings,sharps and pathological waste. Although hazardous,it is distinct from discarded electronic devices.

Option B:
Municipal solid waste is the general household and commercial refuse collected by urban local bodies. It includes food scraps,paper,plastics and similar items. While some electronics may enter this stream,the term is broader and not specific to electronic devices.

Option C:
Agricultural waste originates from farming activities,such as crop residues and animal manure. It does not usually include used computers or mobile phones. Hence it does not correspond to the description in the stem.

Option D:
Electronic waste,or e waste,includes obsolete computers,phones,televisions and related components. Because the stem lists exactly these kinds of items,this term matches the intended concept precisely.

Statements A, B and C are correct: A notes the resource recovery potential, B highlights health risks from informal recycling and C explains the EPR approach. Statement D is incorrect because e-waste contains hazardous components that can contaminate air, soil and water, affecting health and environment. Option C, which includes B, C and D, wrongly accepts D and leaves out A, so it cannot be the correct answer. The correct combination must therefore be A, B and C only.

Option A:
Option A is correct because it combines all three true statements and excludes D. It recognises both the opportunity for material recovery and the risks of improper handling, while pointing to policy instruments such as EPR. This aligns well with the unit’s treatment of e-waste.

Option B:
Option B is incorrect as it omits C, thereby ignoring the important regulatory concept of Extended Producer Responsibility in e-waste management. Without C, the description is incomplete.

Option C:
Option C is incorrect because it includes D as a correct statement, which contradicts scientific evidence on the hazards of e-waste. The presence of this false claim makes the combination unacceptable.

Option D:
Option D is incorrect since it pairs A and C with D and leaves out B. It again treats D as correct and fails to acknowledge the serious health risks associated with informal recycling mentioned in B.

The Battery Waste Management Rules adopt a circular-economy approach by making producers responsible for the entire life cycle of batteries. Producers must ensure collection of used batteries, send them to authorised recyclers and meet material-recovery targets. This reduces pollution risks from hazardous battery components and supports resource security by recovering valuable metals. It also aligns with India’s push towards electric mobility and energy storage.

Option A:
This option is incorrect because landfilling and incineration of batteries can release toxic substances into soil and air. The rules aim to minimise such disposal methods.

Option B:
This option correctly states that Extended Producer Responsibility is central to battery management and that recycling and recovery are key obligations.

Option C:
Throwing batteries in regular garbage undermines safe collection and is discouraged by the rules, which require separate handling.

Option D:
Government agencies may regulate and monitor, but producers and private recyclers play crucial roles; the rules do not put all responsibility on the state.

Integrated solid waste management recognises that no single method can address all waste streams effectively. It therefore uses a mix of strategies,applied in a planned hierarchy,from reduction to final disposal. The stem explicitly lists several methods used together in a coordinated way,which is the essence of integrated management. Hence integrated is the correct term.

Option A:
Centralised management would emphasise control by a single authority or facility but does not necessarily imply using a range of methods. It is about governance structure rather than the combination of techniques described in the question.

Option B:
Integrated approaches aim to maximise resource recovery while minimising environmental impacts and landfill use. They require coordination between households,municipal bodies and private operators. This comprehensive nature fits the stem’s description.

Option C:
Exclusive management suggests relying on one primary method,which is contrary to the integrated philosophy. It would not capture the deliberate use of multiple techniques mentioned in the question.

Option D:
Minimal management implies very limited intervention or capacity,which would likely worsen waste problems. It has no established meaning in the technical literature on waste management,so it is not appropriate here.