Q.1 Which of the following gases is primarily responsible for global warming?
Oxygen
Carbon Dioxide
Nitrogen
Helium
Explanation - Carbon dioxide (CO2) is a greenhouse gas that traps heat in the atmosphere, contributing significantly to global warming.
Correct answer is: Carbon Dioxide
Q.2 What is the main cause of acid rain?
Carbon monoxide
Sulfur dioxide
Ozone
Methane
Explanation - Acid rain is primarily caused by sulfur dioxide (SO2) and nitrogen oxides (NOx) reacting with water in the atmosphere to form acids.
Correct answer is: Sulfur dioxide
Q.3 The process of removing pollutants from industrial wastewater is called:
Distillation
Sedimentation
Effluent treatment
Electrolysis
Explanation - Effluent treatment plants (ETPs) are designed to remove harmful pollutants from industrial wastewater before releasing it into the environment.
Correct answer is: Effluent treatment
Q.4 Which of the following is a major ozone-depleting substance?
CFCs
CO2
SO2
Methane
Explanation - Chlorofluorocarbons (CFCs) release chlorine atoms in the stratosphere, which catalytically destroy ozone molecules.
Correct answer is: CFCs
Q.5 The term 'BOD' in water quality analysis stands for:
Biochemical Oxygen Demand
Biological Oxygen Density
Basic Oxide Dissolution
Biochemical Oxidation Degree
Explanation - BOD measures the amount of dissolved oxygen needed by microorganisms to decompose organic matter in water.
Correct answer is: Biochemical Oxygen Demand
Q.6 Which heavy metal is commonly associated with Minamata disease?
Lead
Mercury
Cadmium
Arsenic
Explanation - Minamata disease is caused by mercury poisoning, usually from consumption of contaminated fish.
Correct answer is: Mercury
Q.7 Which gas is primarily responsible for the depletion of the ozone layer?
Nitrogen Oxide
Chlorofluorocarbons
Carbon Monoxide
Methane
Explanation - CFCs release chlorine in the stratosphere, which breaks down ozone molecules.
Correct answer is: Chlorofluorocarbons
Q.8 The major source of photochemical smog is:
Volcanic eruptions
Vehicle emissions
Agricultural runoff
Industrial solid waste
Explanation - Photochemical smog forms when nitrogen oxides and volatile organic compounds from vehicles react in sunlight to produce ozone and other oxidants.
Correct answer is: Vehicle emissions
Q.9 Which of the following is a primary pollutant?
Ozone
Carbon monoxide
Peroxyacyl nitrate
Nitric acid
Explanation - Primary pollutants are emitted directly from a source, such as CO from vehicle exhaust.
Correct answer is: Carbon monoxide
Q.10 Eutrophication in water bodies is mainly caused by:
Heavy metals
Excess nutrients
Thermal pollution
Oil spills
Explanation - Excess nitrogen and phosphorus lead to algal blooms, which deplete oxygen and harm aquatic life.
Correct answer is: Excess nutrients
Q.11 Which process is commonly used to reduce SO2 emissions from power plants?
Flue-gas desulfurization
Electrolysis
Ozonation
Chlorination
Explanation - Flue-gas desulfurization removes sulfur dioxide from exhaust gases before they enter the atmosphere.
Correct answer is: Flue-gas desulfurization
Q.12 Which of the following compounds is a major greenhouse gas?
Carbon Dioxide
Sulfur Dioxide
Nitrogen
Oxygen
Explanation - Carbon dioxide traps heat in the atmosphere, contributing to the greenhouse effect.
Correct answer is: Carbon Dioxide
Q.13 Which of the following metals is often found in industrial wastewater and is toxic to humans?
Iron
Zinc
Cadmium
Calcium
Explanation - Cadmium is highly toxic and can cause kidney damage and bone defects when present in water.
Correct answer is: Cadmium
Q.14 What is the major effect of CO (carbon monoxide) on human health?
Neurological disorders
Blood oxygen reduction
Kidney failure
Skin irritation
Explanation - CO binds with hemoglobin, reducing oxygen transport in the blood, which can be fatal.
Correct answer is: Blood oxygen reduction
Q.15 Which water pollutant is responsible for the 'blue baby syndrome'?
Nitrate
Lead
Mercury
Phosphate
Explanation - High nitrate levels in drinking water can cause methemoglobinemia in infants, leading to 'blue baby syndrome'.
Correct answer is: Nitrate
Q.16 Which of the following is a secondary air pollutant?
Sulfur dioxide
Carbon monoxide
Ozone
Particulate matter
Explanation - Secondary pollutants like ozone are formed by chemical reactions between primary pollutants in the atmosphere.
Correct answer is: Ozone
Q.17 What is the effect of thermal pollution on aquatic life?
Increases dissolved oxygen
Reduces dissolved oxygen
Neutral effect
Enhances photosynthesis
Explanation - Increased water temperature reduces oxygen solubility, harming aquatic organisms.
Correct answer is: Reduces dissolved oxygen
Q.18 The chemical formula of CFC-12, a major ozone-depleting substance, is:
CCl2F2
CF4
CHCl3
C2F6
Explanation - CFC-12 (dichlorodifluoromethane) contains chlorine atoms that catalyze ozone depletion in the stratosphere.
Correct answer is: CCl2F2
Q.19 Which of the following is the primary source of methane in the atmosphere?
Volcanic activity
Landfills and agriculture
Automobile exhaust
Coal combustion
Explanation - Methane is released from anaerobic decomposition of organic matter in landfills and from livestock digestion.
Correct answer is: Landfills and agriculture
Q.20 Which of the following is a major contributor to indoor air pollution?
CFCs
Radon
Ozone
Methane
Explanation - Radon, a radioactive gas, can accumulate indoors and pose serious health risks, including lung cancer.
Correct answer is: Radon
Q.21 Biomagnification refers to:
Increase in pollutants down the food chain
Increase in pollutants up the food chain
Natural purification of water
Depletion of ozone layer
Explanation - Biomagnification occurs when toxic substances accumulate in higher concentrations at successive trophic levels.
Correct answer is: Increase in pollutants up the food chain
Q.22 Which of the following is considered a persistent organic pollutant (POP)?
DDT
Methane
Carbon dioxide
Sulfur dioxide
Explanation - DDT is a pesticide that persists in the environment, bioaccumulates in organisms, and causes long-term ecological damage.
Correct answer is: DDT
Q.23 The main source of lead pollution in urban areas is:
Industrial effluents
Leaded gasoline
Agricultural pesticides
Household detergents
Explanation - Leaded gasoline emits lead particles, which contaminate air and soil, affecting human health.
Correct answer is: Leaded gasoline
Q.24 Which of the following is a major contributor to photochemical smog?
Sulfur dioxide
Nitrogen oxides
Methane
Chlorofluorocarbons
Explanation - Nitrogen oxides from vehicle emissions react with sunlight to form ozone and other components of photochemical smog.
Correct answer is: Nitrogen oxides
Q.25 Which compound is mainly responsible for the greenhouse effect besides CO2?
Ozone
Methane
Sulfur dioxide
Nitrogen
Explanation - Methane is a potent greenhouse gas that traps heat in the atmosphere, contributing to global warming.
Correct answer is: Methane