UGC NET Environmental Science Unit 7 PYQs with Answers & Concepts

UGC NET Environmental Science Unit 7 covers a wide range of waste management concepts, regulations, classifications, and treatment processes. Because of its factual and application-based nature, many aspirants find this unit challenging during revision. One of the most effective ways to prepare for this unit is by practising previous year questions (PYQs), as they highlight frequently tested areas and exam trends. 

Here, we have compiled important UGC NET Environmental Science Unit 7 PYQs with answers and explanations to help you revise key concepts, assess your preparation level, and improve your performance in the exam.

Why Are Unit 7 PYQs Important for UGC NET Environmental Science?

Previous year questions help candidates:

• Understand recurring concepts and themes.

• Identify important waste management rules and regulations.

• Improve accuracy in statement-based questions.

• Strengthen conceptual clarity in waste treatment processes.

• Develop confidence in solving environmental science MCQs.

Many Unit 7 questions are consistently framed around the same concepts with slight modifications, making PYQ practice highly valuable.

UGC NET Environmental Science Unit 7 PYQs

The following questions from the previous year cover some of the most frequently tested topics from Unit 7, including biomedical waste management, recycling, composting, landfill management, and waste regulations. Reviewing these questions with their concepts can help candidates strengthen their preparation and identify important exam-focused areas.

1. In biomedical waste management, anatomical waste is collected in which colour container?

Answer: Yellow container

Concept: Anatomical waste, including human tissues, organs, and body parts, is categorized under the yellow waste stream.

2. Which colour container is used for collecting sharps such as blades and needles?

Answer: White container

Concept: White containers are designated for sharps waste because of the risk of injury and infection.

3. Which microorganisms initiate the composting process?

Answer: Mesophilic microorganisms

Concept: Mesophilic microbes begin decomposition under moderate temperature conditions before thermophilic organisms become active.

4. Which plastic type is widely recycled worldwide?

Answer: PET (Polyethylene Terephthalate)

Concept: PET bottles are among the most commonly recycled plastic products.

5. Which type of plastic can be remoulded and recycled?

Answer: Thermoplastic

Concept: Thermoplastics soften on heating and can be reshaped, whereas thermosetting plastics cannot.

6. Arrange biomass sources in increasing order of available energy per unit mass.

Answer: Dry municipal sewage waste → Animal waste → Straw → Wood chips and forest residues

Concept: Energy content generally increases with higher lignocellulosic material concentration.

7. Biogas production belongs to which biomass conversion method?

Answer: Biochemical conversion

Concept: Microorganisms convert organic matter into methane-rich biogas.

8. Arrange the stages of biogasification in the correct order.

Answer: Hydrolysis → Acidogenesis → Acetogenesis → Methanogenesis

Concept: This sequence is frequently asked in PYQs and statement-based questions.

9. Which resin code corresponds to PET plastic?

Answer: Code 1

Concept: Important plastic resin codes include PET (1), HDPE (2), PVC (3), LDPE (4), PP (5), PS (6), and Mixed Plastic (7).

10. Environmental Protection (End-of-Life Vehicle) Rules apply to whom?

Answer: Vehicle owners, registered vehicle scrapping facilities, manufacturers, and recyclers.

Concept: Questions from newly introduced waste management regulations are increasingly common in examinations.

11. What are microplastics?

Answer: Small plastic particles generally less than 5 mm in size.

Concept: Microplastic pollution is an emerging environmental concern and a frequently tested topic.

12. Which term is not included in the definition of disaster under the Disaster Management Act, 2005?

Answer: Risk

Concept: This is a notable previous year question that often surprises candidates.

13. What is mineralization during biological degradation?

Answer: Complete conversion of organic matter into inorganic products such as carbon dioxide and water.

Concept: Mineralization represents the final stage of biodegradation.

14. Which condition is essential for composting?

Answer: Adequate moisture and aeration

Concept: Composting microorganisms require oxygen and moisture for efficient decomposition.

15. Which properties are used to classify hazardous waste?

Answer: Ignitability, Reactivity, Toxicity, and Corrosivity

Concept: These characteristics are fundamental in hazardous waste identification.

16. EPR is applicable to which waste streams?

Answer: Plastic waste, E-waste, Battery waste, Used oil, and Waste tyres

Concept: EPR places responsibility on producers for post-consumer waste management.

17. According to Solid Waste Management Rules, a landfill should be located at least how far from a river?

Answer: 100 metres

Concept: Landfill siting criteria are frequently tested through direct and statement-based questions.

18. When is approval of a waste management plan mandatory under Construction and Demolition Waste Management Rules?

Answer: For projects generating 20 tonnes of waste per day or 300 tonnes per project per month.

19. Arrange waste management options from most desirable to least desirable.

Answer: Prevention → Reduction → Recycling → Treatment/Recovery → Disposal

Concept: This hierarchy forms the foundation of sustainable waste management practices.

20. What is waste mining in industrial ecology?

Answer: Recovery of useful resources from waste streams.

Concept: Waste mining supports circular economy principles and resource recovery.

Important Topics Covered in UGC NET Environmental Science Unit 7 PYQs

Before solving PYQs, candidates should revise the following topics:

• Municipal Solid Waste Management

• Biomedical Waste Management

• Hazardous Waste Management

• Plastic Waste Management

• E-Waste Management

• Construction and Demolition Waste

• Composting and Vermicomposting

• Biogasification

• Landfill Management

• Industrial Ecology

• Extended Producer Responsibility (EPR)

• Waste Management Hierarchy

• Environmental Protection and Waste Rules

Key Revision Tips for Unit 7

UGC NET Environmental Science Unit 7 contains several factual concepts, rules, and process-based topics that are frequently tested in the examination. While revising, focus on important classifications, waste management regulations, and practical applications to improve both accuracy and retention.

• Memorize biomedical waste colour coding.

• Learn plastic resin identification codes from 1 to 7.

• Revise all waste management rules and amendments.

• Practice statement-based questions on EPR and hazardous waste.

• Understand landfill and composting processes conceptually.

• Focus on industrial ecology and circular economy concepts.

• Revise numerical and arrangement-based questions from biogasification and biomass energy.