Energy & Pollution Control MCQs

Correct Answer: a) 300 Giga joules

Explanation:
Global average per capita energy consumption is ~300 GJ/year (80,000 kWh), with developed nations using 2-3 times more than developing countries. This includes all energy forms (electricity, transport, heating, etc.).

Correct Answer: a) 20 million

Explanation:
Approximately 20 million people die annually from hunger/malnutrition-related causes (WHO data). This highlights the link between environmental degradation, agricultural productivity, and human welfare.

Correct Answer: d) DDT

Explanation:
DDT (Dichloro-Diphenyl-Trichloroethane) is a persistent organic pollutant that bioaccumulates in food chains. Though banned in many countries, its residues remain in ecosystems for decades, affecting top predators like birds of prey.

Correct Answer: d) Petroleum

Explanation:
Petroleum fuels 90% of global transportation and is feedstock for plastics, fertilizers, and chemicals. Its price fluctuations significantly impact world economies, earning it the "lifeline" designation despite environmental concerns.

Correct Answer: a) Coal

Explanation:
India has the world's 5th largest coal reserves (319 billion tons), meeting 55% of its primary energy needs. Domestic coal production supports electricity generation (72% of power) and heavy industries like steel and cement.

Correct Answer: b) Compressed Natural Gas (CNG)

Explanation:
CNG burns cleaner than gasoline/diesel, emitting 20-30% less CO₂, 90% fewer particulates, and negligible sulfur oxides. Delhi's CNG vehicle program (since 1998) reduced air pollution by ~30%, serving as a global model.

Correct Answer: d) All the above

Explanation:
Biomass energy utilizes organic materials: crop residues (rice husks, bagasse), livestock waste (gobar), wood chips, and dedicated energy crops. India generates ~500 million tons of agricultural biomass annually, with 150-200 million tons available for energy production.

Correct Answer: d) Jatropha curcas & oil palms

Explanation:
Jatropha (30-40% oil content) and oil palms (highest yield at 4,000 liters/hectare/year) are prime biodiesel sources. India's National Biodiesel Mission promotes Jatropha cultivation on wastelands for energy security.

Correct Answer: c) Methane, CO₂, H₂, H₂S

Explanation:
Typical biogas contains 50-75% methane (CH₄), 25-50% CO₂, 1-5% hydrogen (H₂), and traces of hydrogen sulfide (H₂S). The energy content (~20-25 MJ/m³) depends on methane concentration, with impurities removed before use.

Correct Answer: a) Methane

Explanation:
Anaerobic digestion (without oxygen) by methanogenic bacteria converts organic matter into methane-rich biogas through four stages: hydrolysis, acidogenesis, acetogenesis, and methanogenesis. This natural process occurs in landfills, wetlands, and animal digestive systems.

Correct Answer: d) Biogas

Explanation:
While no energy is completely pollution-free, biogas is considered nearly so as it recycles organic waste, produces minimal emissions when burned (mainly CO₂ which was recently absorbed by plants), and prevents methane release from decomposing waste.

Correct Answer: b) Hydrogen fuels

Explanation:
Hydrogen fuel cells (combining H₂ and O₂ to produce electricity with water as byproduct) offer zero-emission potential. Challenges include green hydrogen production (via renewable-powered electrolysis) and storage/transport infrastructure development.

Correct Answer: a) 284 kJ/mol

Explanation:
The combustion of hydrogen (2H₂ + O₂ → 2H₂O) releases 286 kJ/mol at standard conditions, with fuel cells extracting ~284 kJ as usable electricity. This high energy density (142 MJ/kg) makes hydrogen attractive for aviation and heavy transport.

Correct Answer: b) Light Emitting Diode

Explanation:
LEDs are semiconductor devices that emit light when current flows through them. They use 75% less energy than incandescent bulbs and last 25 times longer. India's UJALA scheme distributed 367 million LEDs, saving ~47 billion kWh annually.