1. : The main combustible gas present in biogas is?
(A) Carbon dioxide
(B) Methane
(C) Oxygen
(D) Nitrogen
2. : Typical methane content in biogas is about?
(A) 10–20%
(B) 40–70%
(C) 80–90%
(D) 95–100%
3. : The calorific value of biogas is approximately?
(A) 2,000 kcal/m³
(B) 5,000 kcal/m³
(C) 15,000 kcal/m³
(D) 25,000 kcal/m³
4. : Anaerobic digestion for biogas production occurs in?
(A) Presence of oxygen
(B) Absence of oxygen
(C) Sunlight only
(D) High-pressure chamber
5. : The commonly used biogas plant model in India is?
(A) Floating drum (KVIC model)
(B) UASB reactor
(C) Downdraft gasifier
(D) Double fluidized bed reactor
6. : Slurry left after biogas production is mainly used as?
(A) Fertilizer
(B) Fuel
(C) Pesticide
(D) Irrigation water only
7. : The main source of feedstock for biogas plants in villages is?
(A) Plastics
(B) Animal dung and crop residues
(C) Coal
(D) Fertilizers
8. : Biomass gasifiers primarily convert biomass into?
(A) Alcohol
(B) Producer gas
(C) Coal tar
(D) Fertilizer
9. : The main components of producer gas are?
(A) CO, H₂, CH₄, and N₂
(B) O₂ and CO₂
(C) SO₂ and H₂S
(D) NH₃ and CH₄
10. : Biogas production is maximum at a temperature of?
(A) 0–10 °C
(B) 25–35 °C
(C) 55–65 °C
(D) 100 °C
11. : Which microorganism group is mainly responsible for methane production?
(A) Fungi
(B) Methanogenic bacteria
(C) Algae
(D) Viruses
12. : The retention period of slurry in a typical biogas plant is about?
(A) 2–3 days
(B) 20–30 days
(C) 60–90 days
(D) 120 days
13. : Which gas in biogas causes corrosion in pipelines?
(A) Methane
(B) Carbon dioxide
(C) Hydrogen sulfide
(D) Nitrogen
14. : The main advantage of biogas over biomass combustion is?
(A) Higher efficiency and cleaner burning
(B) Higher smoke emission
(C) Greater ash residue
(D) More deforestation
15. : Biomass power plants generate electricity mainly through?
(A) Combustion and steam turbines
(B) Nuclear fission
(C) Hydropower
(D) Solar PV
16. : The fixed dome type biogas plant is also known as?
(A) Deenbandhu model
(B) KVIC model
(C) Downdraft model
(D) Fluidized model
17. : Biogas is considered a renewable energy because?
(A) It is derived from fossil fuels
(B) It uses continuously available organic matter
(C) It is produced only once
(D) It increases greenhouse gases
18. : The main limitation of biogas plants in cold regions is?
(A) High methane content
(B) Reduced microbial activity at low temperature
(C) Excess slurry production
(D) Low cost of installation
19. : Biomass briquettes are mainly made by?
(A) Mixing coal and oil
(B) Compressing crop residues and sawdust
(C) Fermenting sugarcane juice
(D) Gasifying biomass
20. : The heating value of biomass depends largely on?
(A) Nitrogen content
(B) Moisture content
(C) Soil type
(D) Sunlight exposure
21. : Gasification of biomass takes place in the presence of?
(A) Excess oxygen
(B) Limited oxygen
(C) No oxygen
(D) Only nitrogen
22. : Which of the following is a liquid biofuel derived from biomass?
(A) Ethanol
(B) Methane
(C) Producer gas
(D) Hydrogen
23. : The pH range suitable for anaerobic digestion in biogas plants is?
(A) 2–3
(B) 4–5
(C) 6.5–7.5
(D) 9–10
24. : The main by-product of biomass gasification apart from producer gas is?
(A) Charcoal
(B) Biogas
(C) Crude oil
(D) Glycerol
25. : The ultimate goal of biogas and biomass energy systems is to?
(A) Increase deforestation
(B) Provide clean, renewable, and sustainable energy for rural areas
(C) Increase dependence on fossil fuels
(D) Reduce agricultural productivity