81. Which of the following pollutants is primarily responsible for smog formation?
A) Ozone and particulate matter
B) Carbon monoxide and water vapor
C) Methane and oxygen
D) Nitrogen gas and argon
Answer: A) Ozone and particulate matter
Explanation:
Smog, particularly photochemical smog, is formed when pollutants like nitrogen oxides (NOx) and volatile organic compounds (VOCs) react in the presence of sunlight to produce ozone. Particulate matter also contributes to the haze and poor air quality associated with smog.
82. Which of the following is the main cause of thermal pollution in water bodies?
A) Sewage discharge
B) Industrial effluents
C) Fossil fuel combustion
D) Deforestation
Answer: B) Industrial effluents
Explanation:
Thermal pollution occurs when industries, especially power plants, release hot water or other effluents into water bodies. The elevated water temperature lowers oxygen levels, negatively affecting aquatic life and ecosystem balance.
83. What is the primary environmental issue caused by excessive use of nitrogen-based fertilizers?
A) Global warming
B) Ozone depletion
C) Eutrophication
D) Acid rain
Answer: C) Eutrophication
Explanation:
Excessive use of nitrogen-based fertilizers leads to eutrophication when runoff containing nitrates enters water bodies. This stimulates excessive algae growth, depleting oxygen in the water and causing dead zones, which harm aquatic ecosystems.
84. Which of the following is a common consequence of eutrophication in lakes and rivers?
A) Increased oxygen levels
B) Decrease in biodiversity
C) Lower water temperatures
D) Reduced water flow
Answer: B) Decrease in biodiversity
Explanation:
Eutrophication leads to algal blooms, which consume oxygen when they decompose. This reduces oxygen levels in the water, causing hypoxia (low oxygen), which can lead to the death of aquatic organisms and a decrease in biodiversity.
85. Which of the following methods is used to measure air quality?
A) pH meter
B) Anemometer
C) Air Quality Index (AQI)
D) Hydrometer
Answer: C) Air Quality Index (AQI)
Explanation:
The Air Quality Index (AQI) is a tool used to measure and communicate the quality of air in a specific location. It provides information on pollutant levels, including particulate matter, ozone, sulfur dioxide, and nitrogen dioxide, to help assess the potential health effects.
86. Which of the following is a major source of microplastic pollution in the ocean?
A) Organic farming
B) Urban runoff
C) Fishing nets
D) Textile fibers
Answer: D) Textile fibers
Explanation:
Microplastic pollution in the ocean is often caused by tiny synthetic fibers from textiles, which are shed during washing and make their way into water bodies. These microplastics are harmful to marine life and can enter the food chain.
87. Which of the following is a characteristic of acid rain?
A) It has a neutral pH of 7.
B) It increases soil fertility.
C) It is caused by sulfur dioxide and nitrogen oxides.
D) It improves the pH of aquatic ecosystems.
Answer: C) It is caused by sulfur dioxide and nitrogen oxides.
Explanation:
Acid rain occurs when sulfur dioxide (SO₂) and nitrogen oxides (NOx) in the atmosphere react with water vapor to form sulfuric acid and nitric acid. This acidic precipitation lowers the pH of soil and water, harming ecosystems, buildings, and human health.
88. Which of the following is an effect of overgrazing on soil?
A) Increased water retention
B) Enhanced soil fertility
C) Soil erosion
D) Improved vegetation cover
Answer: C) Soil erosion
Explanation:
Overgrazing by livestock removes vegetation that protects the soil, leading to soil erosion. Without plants to hold the soil in place, wind and water can easily erode it, reducing its fertility and leading to land degradation.
89. Which of the following is a consequence of ocean acidification?
A) Enhanced coral growth
B) Increased fish populations
C) Coral bleaching
D) Reduced methane emissions
Answer: C) Coral bleaching
Explanation:
Ocean acidification occurs as a result of increased CO₂ absorption by seawater, which lowers the pH and reduces carbonate ion availability. This hinders the ability of marine organisms, like corals and shellfish, to form their skeletons, leading to coral bleaching and ecosystem disruption.
90. Which of the following is a renewable energy source that can reduce air pollution?
A) Natural gas
B) Coal
C) Wind power
D) Oil
Answer: C) Wind power
Explanation:
Wind power is a renewable energy source that generates electricity without emitting air pollutants or greenhouse gases. It helps reduce reliance on fossil fuels and mitigates the environmental impacts of air pollution and climate change.
Leave a comment