Q11. Which of the following is classified as a secondary pollutant?
Environmental and Ecological Changes and Impact Assessment: RAS Prelims MCQs
168 RAS Prelims MCQs on environmental and ecological changes and impact assessment cover ecosystem concepts, pollution, climate and environmental law. Ecotones, decomposers, primary productivity, secondary pollutants, the greenhouse effect, the EIA Notification 2006, the Environment (Protection) Act 1986 and the Aravalli mining ban are asked as definitions, laws and statements.
Practice questions based on the RPSC RAS Prelims syllabus. They follow the exam pattern but are not past-paper questions.
Showing 11–20 of 168 questions
Q12. Non-point source pollution refers to:
Explanation
Unlike pollution that comes from a single, identifiable pipe or chimney, some contamination originates from broad and diffuse areas. This type of environmental degradation occurs as water moves over and through the ground, picking up pollutants from varied locations like farm fields or city streets. Because it has no specific point of origin, tracking and controlling this variety is extremely challenging.
Q13. Match List I with List II regarding types of pollution and their common causes:
| Type of Pollution | Common Source/Cause |
|---|---|
| A. Air Pollution | i. Agricultural runoff |
| B. Water Pollution | ii. Excessive use of agrochemicals |
| C. Soil Pollution | iii. Jet engine take-off |
| D. Noise Pollution | iv. Incomplete combustion of fossil fuels |
Explanation
Different human activities lead to various forms of environmental degradation. Burning fuels incompletely releases harmful gases into the air. Runoff from agricultural fields carries fertilizers and chemicals into water bodies. Using excessive pesticides directly contaminates the ground. Finally, high-intensity mechanical activities like aviation produce loud sounds that disturb the peace and health of living beings in the vicinity of the source.
Q14. The term ‘smog’ was originally coined to describe a mixture of:
Explanation
The term used to describe a specific type of intense air pollution was originally created by combining two words. It referred to a thick, dark mixture caused by the combination of coal emissions and natural atmospheric moisture common in industrial cities. While modern versions involve different chemical reactions, the name persists as a general description for visible and harmful atmospheric haze.
Q15. Identify the incorrect statement regarding pollutants.
Explanation
Pollutants are classified based on how they behave in the environment. Substances that are easily broken down by bacteria and fungi are considered biodegradable. However, certain synthetic chemicals, such as some older pesticides, are extremely resistant to natural decay. These persistent compounds remain in the soil and water for decades, often accumulating in the bodies of animals and causing long-term ecological damage.
Q16. Which unit is primarily used to measure the intensity of noise pollution?
Explanation
Sound intensity is measured using a logarithmic scale that reflects how the human ear perceives different levels of pressure. This unit helps quantify the loudness of sounds, ranging from a quiet whisper to the deafening roar of a jet engine. Identifying these levels is crucial for establishing safety regulations and protecting public health from the adverse effects of excessive acoustic energy.
Q17. Consider the following statements about persistent organic pollutants (POPs):
I. They remain intact in the environment for long periods.
II. They become widely distributed geographically.
III. They accumulate in the fatty tissue of living organisms.
IV. They are highly water-soluble.
V. They are toxic to humans and wildlife.
Which of the above statement(s) is/are correct?
I. They remain intact in the environment for long periods.
II. They become widely distributed geographically.
III. They accumulate in the fatty tissue of living organisms.
IV. They are highly water-soluble.
V. They are toxic to humans and wildlife.
Which of the above statement(s) is/are correct?
Explanation
Persistent organic pollutants are dangerous chemicals that resist natural degradation and stay in the environment for very long periods. Because they are generally fat-soluble and have low solubility in water, they easily accumulate in the adipose tissues of living creatures. These toxins can travel vast distances through air and water currents, eventually reaching and harming wildlife even in remote polar regions.
Q18. Thermal pollution in water bodies is primarily caused by:
Explanation
Thermal pollution occurs when the temperature of a natural water body is suddenly changed, usually by human activity. The most frequent cause is the use of water as a coolant in large industrial facilities and electricity generating stations. When this heated water is returned to the original source, it decreases dissolved oxygen levels and harms fish and other aquatic organisms.
Q19. Which of the following diseases is primarily associated with noise pollution?
Explanation
Constant exposure to high levels of sound can lead to various physical and psychological health problems. Beyond hearing loss, chronic loud environments trigger stress responses in the body, which can result in increased blood pressure. This condition significantly raises the risk of heart disease and other cardiovascular issues, highlighting the serious nature of acoustic disturbances as a major environmental health concern.
Q20. Which gas binds with hemoglobin in the blood to reduce its oxygen-carrying capacity?
Explanation
A colorless and odorless gas is produced when fuels containing carbon are burned without enough oxygen. When inhaled, this substance has a much higher affinity for the oxygen-carrying protein in red blood cells than oxygen itself. By forming a stable complex, it prevents the blood from delivering vital oxygen to the body’s tissues and organs, which can be fatal at high levels.Answer key for these questions
| Q | Correct answer |
|---|---|
| 11 | (b) Ground-level Ozone (O₃) |
| 12 | (b) Pollution from diffuse and widespread sources |
| 13 | (a) A-iv, B-i, C-ii, D-iii |
| 14 | (c) Smoke and fog |
| 15 | (d) DDT is a classic example of a biodegradable pollutant. |
| 16 | (c) Decibel |
| 17 | (a) I, II, III and V |
| 18 | (d) Discharge of heated water from power plants |
| 19 | (a) Hypertension |
| 20 | (c) Carbon monoxide |
Key facts from Environmental and Ecological Changes and Impact Assessment
- An ecosystem is made of interacting organisms and their physical environment; an ecotone is a zone of transition between ecosystems.
- Saprotrophs convert complex organic matter into simple substances; gross primary productivity is the rate at which producers create organic matter.
- Plants release water vapour through transpiration.
- Ground-level ozone is a secondary pollutant; CO, SO₂ and PM10 are primary pollutants.
- The greenhouse effect is the trapping of heat by atmospheric gases.
- Category B2 projects are exempt from public consultation under the EIA Notification 2006; the Supreme Court banned mining in the Aravalli range in Haryana and Rajasthan.
Frequently asked questions
How many RAS Prelims practice MCQs are there on Environmental and Ecological Changes and Impact Assessment?
This page has 168 practice MCQs on Environmental and Ecological Changes and Impact Assessment (Health, Environment and Agriculture). Each has the correct answer, and most have an explanation.
What is a secondary pollutant?
A pollutant that is not emitted directly but forms in the air from primary pollutants. Ground-level ozone is the standard example, formed when nitrogen oxides and volatile organic compounds react in sunlight.
What is an ecotone?
A zone of transition between two different ecosystems, such as the area between a forest and a grassland. It often has more species than either neighbour because it has species of both.
Which projects are exempt from public consultation under EIA 2006?
Category B2 projects, which have less environmental impact. Category A and B1 projects need public consultation as part of the clearance process, which is the main way local people are heard.