Tag: science & technology

Nek Chand's famous Rock Garden, also known as the 'Rock Garden of Chandigarh,' is an iconic 25-acre sculpture garden created entirely from industrial and household waste. It is located in Chandigarh, not Chennai, Lucknow, or Bangalore. The garden features sculptures made from recycled materials like broken bangles, tiles, and electrical fittings.

Approximately 79% of Earth's surface is covered by water, but only about 1% of this total is readily available freshwater for human consumption (most is saltwater or locked in glaciers/ice caps). The other options present incorrect figures. This statistic highlights the critical scarcity of accessible freshwater resources despite Earth appearing 'water-rich.'

Maharashtra became the first state in India to introduce environmental education as a separate compulsory subject in schools. This pioneering decision was taken in 2001, making environmental education mandatory from classes 1 to 12. Other states followed this initiative later.

Both green manure and biofertilizers are biological materials used to enhance soil fertility. Green manure involves growing plants and plowing them back into the soil, while biofertilizers contain living microorganisms that fix nutrients. Bioinsecticides are used for pest control, not soil fertility.

Freon is the trade name for chlorofluorocarbons (CFCs) commonly used as refrigerants in refrigerators and air conditioning systems. Carbon dioxide, methane, and ammonia are not CFCs - methane and CO2 are greenhouse gases, while ammonia is a different refrigerant. CFCs are potent greenhouse gases due to their high global warming potential.

Silicon is the second most abundant element in Earth's crust (about 28% by mass) after oxygen. Solar cells, or photovoltaic cells, are primarily made from silicon due to its semiconductor properties. Bauxite is an aluminum ore, while calcium and magnesium are metals not used in photovoltaic applications.

Methane (CH4) is produced in all the listed sources: landfills, anaerobic decomposition in marshes and paddy fields, by ruminant animals during digestion, and by termites. It is also released during biomass burning. Methane has 21-25 times more global warming potential than CO2 over 100 years, making it a potent greenhouse gas.

Sea level rise is one of the most widely discussed and studied impacts of climate change, resulting from thermal expansion of seawater and melting ice sheets and glaciers. Deforestation and soil erosion are environmental problems but not direct climate change impacts, and they're less frequently discussed in climate change discourse than sea level rise.

The Sun's composition is primarily hydrogen (about 74% by mass, 92% by volume) with helium making up most of the remainder (about 24-25% by mass). Hydrogen is the fuel for the nuclear fusion reactions that power the Sun. Oxygen and carbon are present only in trace amounts (less than 1% combined).

The Sun is a star, specifically a G-type main-sequence star (G2V). It generates energy through nuclear fusion in its core, converting hydrogen into helium. A planet orbits a star (like Earth orbits the Sun). A comet is an icy body that develops a tail when near the Sun. A meteoroid is a small rocky or metallic body in space.