Q1. The “Four R’s” in waste management include all EXCEPT:
- Refuse
- Replace
- Reduce
- Reuse
Correct Option: 2. Replace
Explanation: The Four R’s are Refuse, Reduce, Reuse, and Recycle. “Replace” is not part of the standard four R’s in sustainable waste management.
Q2. What is the safe indoor noise level as recommended by the WHO?
- 50 dB
- 40 dB
- 30 dB
- 60 dB
Correct Option: 3. 30 dB
Explanation: The World Health Organization (WHO) recommends indoor noise levels to be below 30 decibels to avoid adverse health effects like stress and sleep disturbances.
Q3. What is the most common environmental effect of light pollution?
- Coral bleaching
- Disruption of nocturnal animal behavior
- Soil fertility increase
- Acid rain
Correct Option: 2. Disruption of nocturnal animal behavior
Explanation: Light pollution disrupts the natural activities of nocturnal animals (e.g., migration, feeding, and reproduction) by mimicking daylight conditions at night.
Q4. Which of the following control methods helps reduce both soil and thermal pollution?
- Afforestation
- Sprinkler irrigation
- Pesticide application
- Use of air purifiers
Correct Option: 1. Afforestation
Explanation:
Afforestation (planting trees) helps in:
• Soil conservation (prevents erosion and pollution),
• Reducing thermal pollution by shading water bodies and lowering temperature.
Q5. Which of the following methods is used in industries to reduce thermal pollution by cooling heated water before discharging it?
- Reverse osmosis
- Cooling towers
- Bioremediation
- Incineration
Correct Option: 2. Cooling towers
Explanation:
Cooling towers and cooling ponds are widely used in industries and power plants to dissipate excess heat from water before releasing it into natural water bodies. This helps reduce thermal pollution, preventing sudden temperature changes that can harm aquatic ecosystems.
• Cooling towers allow heat to escape through evaporation.
• Cooling ponds hold heated water until it cools naturally.