General Science/Everyday Science MCQs
Topic Notes: General Science/Everyday Science
MCQs and preparation resources for competitive exams, covering important concepts, past papers, and detailed explanations.
Plato
- Biography: Ancient Greek philosopher (427–347 BCE), student of Socrates and teacher of Aristotle, founder of the Academy in Athens.
- Important Ideas:
- Theory of Forms
- Philosopher-King
- Ideal State
171
A key characteristic of persistent organic pollutants (POPs) is:
Answer:
Long-range atmospheric transport
POPs resist breakdown, bioaccumulate, and can travel far from sources. The Stockholm Convention targets many POPs. They pose chronic ecological and health risks.
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172
The main goal of biodiversity offsets is to:
Answer:
iodiversity offsets is to:
Offsets compensate for residual impacts after avoidance and minimization. They must be additional, measurable, and long-term. Poorly designed offsets risk greenwashing.
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173
A typical coagulant used in water treatment is:
Answer:
Aluminum sulfate (alum)
Alum destabilizes colloids to form flocs that settle. Ferric salts are alternatives. Coagulation improves turbidity and pathogen removal.
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174
The “polluter pays” principle means:
Answer:
Responsible party bears prevention and remediation costs
It internalizes environmental externalities. It incentivizes pollution control and safer design. Many regulations embed this principle.
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175
A fast-growing plant used widely in phytoremediation is:
Answer:
Water hyacinth (controlled use)
Its high uptake can remove nutrients and some metals from water. However, it is invasive; strict containment is necessary. Alternatives include duckweed or constructed wetlands.
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176
The best single indicator of river health among these is:
Answer:
Benthic macroinvertebrate index
Community composition integrates multiple stressors over time. Sensitive taxa decline under pollution. Biological indices complement physicochemical metrics.
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177
The species most at risk from bycatch in longline fisheries is often:
Answer:
Sea turtle
Turtles are accidentally hooked and drowned. Mitigation includes circle hooks, bait changes, and time–area closures. Bycatch reduction devices save many non-target species.
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178
The safest household disinfectant for maintaining residual protection in piped water is:
Answer:
Chlorine
Chlorine provides a lasting residual in distribution networks. Ozone and UV have no residual effect, requiring point-of-contact treatment. Boiling is effective but offers no residual.
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179
The most effective indoor radon mitigation is:
Answer:
Sub-slab depressurization (active ventilation)
A fan-driven system vents soil gases before they enter the building. Sealing cracks helps but is insufficient alone. Testing is essential in high-radon areas.
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180
The El Niño phenomenon typically leads to:
Answer:
Warmer central/eastern Pacific and altered rainfall patterns
El Niño weakens trade winds, shifts convection, and changes global weather. Some regions see drought; others see floods. It also boosts global mean temperatures.
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