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
341
The maximum permissible concentration of fluoride in drinking water is:
Answer:
1.50 mg/L
The WHO guideline sets 1.5 mg/L as the safe limit for fluoride in drinking water. Below this, it prevents dental caries, but higher levels cause fluorosis. National standards often align with this limit.
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342
Among nutrients in fertilizers, which causes the least water pollution?
Answer:
Potassium
Nitrogen and phosphorus are the main drivers of eutrophication. Organic matter can deplete oxygen if untreated. Potassium, however, has minimal impact on water quality compared to the others.
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343
India has the largest share of which mineral resource?
Answer:
Mica
India is the world’s leading producer of mica, used in electronics, paints, and cosmetics. It also has significant manganese reserves but ranks second to other countries. Mica exports are a major foreign exchange source.
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344
Which statement about forests is NOT correct?
Answer:
None of the above
All the listed statements are correct. Forests provide ecological, social, and economic benefits. Hence, no statement here is incorrect.
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345
Blue Baby Syndrome (methemoglobinemia) is caused by water contamination with:
Answer:
Nitrates
Excess nitrates in drinking water interfere with oxygen transport in infants’ blood, leading to “blue baby syndrome.” It is linked to agricultural runoff and poor water treatment. This condition can be life-threatening.
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346
Major causes of deforestation include:
Answer:
All of the above
Deforestation is driven by agriculture, logging, industrial demands, and fuel needs. It reduces biodiversity, disrupts water cycles, and contributes to climate change. Multifaceted strategies are needed to address it.
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347
Forests prevent soil erosion mainly through their:
Answer:
Roots
Roots bind soil particles, reducing erosion by wind and water. Forests also reduce runoff and act as natural barriers. Leaves and stems provide cover, but roots are most effective in anchoring soil.
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348
During photosynthesis, trees produce:
Answer:
Oxygen
Plants use carbon dioxide and sunlight to produce glucose and release oxygen. This oxygen supports life across ecosystems. Photosynthesis is the foundation of Earth’s energy and oxygen cycles.
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349
About what percentage of Earth’s surface is covered by water?
Answer:
bout what percentage of Earth’s surface is covered by water?
Oceans, seas, lakes, and rivers cover about 71% of Earth’s surface. Most of it is saltwater, with only 2.5% as freshwater. This figure highlights Earth’s identity as the “blue planet.”
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350
What percentage of a country’s geographical area should ideally be under forest cover?
Answer:
33%
The National Forest Policy of India (1988) recommends at least one-third of land under forest for ecological stability. Higher coverage is targeted in hilly regions. Many countries aim for similar benchmarks.
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