Q.1 Which of the following gases is primarily responsible for global warming?
Oxygen
Carbon Dioxide
Nitrogen
Hydrogen
Explanation - Carbon dioxide (CO2) traps heat in the atmosphere, leading to the greenhouse effect and global warming.
Correct answer is: Carbon Dioxide
Q.2 What is the main cause of acid rain?
Carbon monoxide emissions
Sulfur dioxide and nitrogen oxides
Ozone depletion
Methane emissions
Explanation - Acid rain forms when sulfur dioxide (SO2) and nitrogen oxides (NOx) react with water in the atmosphere to produce acids.
Correct answer is: Sulfur dioxide and nitrogen oxides
Q.3 The ozone layer is located in which layer of Earth's atmosphere?
Troposphere
Stratosphere
Mesosphere
Thermosphere
Explanation - The ozone layer is concentrated in the stratosphere and protects life on Earth from harmful ultraviolet radiation.
Correct answer is: Stratosphere
Q.4 Which of the following is a renewable source of energy?
Coal
Natural Gas
Solar Power
Petroleum
Explanation - Solar power is renewable as it is derived from sunlight, which is naturally replenished.
Correct answer is: Solar Power
Q.5 Which process converts atmospheric nitrogen into a form usable by plants?
Photosynthesis
Nitrogen Fixation
Respiration
Transpiration
Explanation - Nitrogen-fixing bacteria convert atmospheric nitrogen (N2) into ammonia or related compounds usable by plants.
Correct answer is: Nitrogen Fixation
Q.6 Which of the following is a major cause of soil erosion?
Deforestation
Ozone depletion
Global warming
Acid rain
Explanation - Removing trees reduces the root structure that holds soil, increasing soil erosion.
Correct answer is: Deforestation
Q.7 Which pollutant is most responsible for the formation of smog in urban areas?
Sulfur dioxide
Nitrogen oxides
Particulate matter
Ozone
Explanation - Nitrogen oxides react with volatile organic compounds (VOCs) under sunlight to form photochemical smog.
Correct answer is: Nitrogen oxides
Q.8 What is the main consequence of deforestation on climate?
Decrease in rainfall
Increase in biodiversity
Increase in oxygen levels
Decrease in carbon dioxide levels
Explanation - Deforestation reduces transpiration, which lowers rainfall and alters local climate patterns.
Correct answer is: Decrease in rainfall
Q.9 Which of the following contributes most to the greenhouse effect?
Methane
Oxygen
Argon
Neon
Explanation - Methane (CH4) is a potent greenhouse gas that traps heat in the atmosphere more effectively than CO2.
Correct answer is: Methane
Q.10 Which international agreement aims to reduce greenhouse gas emissions?
Kyoto Protocol
Montreal Protocol
Geneva Convention
Paris Accord
Explanation - The Kyoto Protocol set binding targets for industrialized countries to reduce greenhouse gas emissions.
Correct answer is: Kyoto Protocol
Q.11 Eutrophication in water bodies is primarily caused by:
Excess nutrients
Thermal pollution
Oil spills
Plastic waste
Explanation - Runoff rich in nitrogen and phosphorus from fertilizers leads to excessive algae growth, depleting oxygen in water.
Correct answer is: Excess nutrients
Q.12 Which type of waste is biodegradable?
Plastic bottles
Glass
Food scraps
Electronic waste
Explanation - Biodegradable waste can be broken down naturally by microorganisms, such as food scraps and plant residues.
Correct answer is: Food scraps
Q.13 Which is the main cause of marine oil pollution?
Agricultural runoff
Industrial effluents
Oil spills from ships
Plastic bags
Explanation - Accidental or deliberate oil discharge from ships contaminates oceans and affects marine life.
Correct answer is: Oil spills from ships
Q.14 Which of the following is NOT a greenhouse gas?
Water vapor
Methane
Carbon dioxide
Oxygen
Explanation - Oxygen is essential for life but does not trap heat; hence it is not a greenhouse gas.
Correct answer is: Oxygen
Q.15 Biomagnification refers to:
Accumulation of toxins in soil
Increase in toxin concentration along the food chain
Reduction of oxygen in water
Pollution of air by particulates
Explanation - Toxins like pesticides accumulate in organisms, increasing in concentration as they move up the food chain.
Correct answer is: Increase in toxin concentration along the food chain
Q.16 Which energy source is considered non-renewable?
Wind energy
Geothermal energy
Coal
Solar energy
Explanation - Coal is finite and takes millions of years to form, making it a non-renewable energy source.
Correct answer is: Coal
Q.17 Which is the primary source of indoor air pollution in rural homes?
Automobile exhaust
Biomass burning
Industrial emissions
Pollen
Explanation - Burning wood, crop residues, or dung indoors releases smoke and harmful gases, leading to indoor air pollution.
Correct answer is: Biomass burning
Q.18 Which of the following is a consequence of ozone layer depletion?
Global warming
Increased UV radiation
Acid rain
Earthquake frequency increase
Explanation - Thinning of the ozone layer allows more harmful ultraviolet radiation to reach the Earth's surface, causing health hazards.
Correct answer is: Increased UV radiation
Q.19 Which method is commonly used for wastewater treatment?
Distillation
Sedimentation
Filtration with sand
Electrolysis
Explanation - Sedimentation allows suspended solids in wastewater to settle at the bottom, facilitating further treatment.
Correct answer is: Sedimentation
Q.20 Which is the largest source of freshwater on Earth?
Rivers
Glaciers
Lakes
Groundwater
Explanation - Glaciers and ice caps store about 68% of Earth's freshwater, far more than rivers or lakes.
Correct answer is: Glaciers
Q.21 Which gas is primarily responsible for the depletion of the ozone layer?
Carbon dioxide
CFCs (Chlorofluorocarbons)
Methane
Nitrous oxide
Explanation - CFCs release chlorine atoms in the stratosphere, which break down ozone molecules.
Correct answer is: CFCs (Chlorofluorocarbons)
Q.22 Which of the following is considered a non-point source of water pollution?
Industrial discharge pipe
Sewage treatment plant effluent
Agricultural runoff
Oil refinery outlet
Explanation - Non-point source pollution comes from diffuse sources, such as fertilizers and pesticides washed off fields.
Correct answer is: Agricultural runoff