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100 questions in this collection · Page 8 of 10
Question 71 of 100
📘 CLASS XII
Environmental Issues
Read the following statements regarding Hospital and Electronic waste:
I. Hospitals generate hazardous wastes containing disinfectants, harmful chemicals, and pathogens. II. The use of incinerators is crucial for the safe disposal of hospital waste. III. Irreparable computers and other electronic goods are known as electronic wastes (e-wastes). IV. E-wastes are either buried in landfills or incinerated.
Which of the statements given above are correct?
All four statements are correct. Hospital waste contains hazardous chemicals and pathogens requiring incineration. Defunct electronic devices constitute e-waste, which is commonly disposed of through landfilling or incineration.
Question 72 of 100
📘 CLASS XII
Environmental Issues
With reference to the recycling of Electronic Waste, consider the following statements:
I. Over half of the e-wastes generated in the developed world are exported to developing nations like China, India, and Pakistan. II. Recycling of e-waste allows the recovery of valuable metals such as copper, iron, silicon, nickel, and gold. III. Unlike developed countries, recycling in developing nations often involves manual participation. IV. Manual recycling in developing countries is highly safe because the electronic parts are pre-treated.
Which of the statements given above are correct?
Statements I, II and III are correct. More than half of the e-waste generated in developed countries is exported to developing nations. Recycling recovers valuable metals, but in developing countries it is often performed manually, exposing workers to toxic substances. Therefore, Statement IV is incorrect.
Question 73 of 100
📘 CLASS XII
Environmental Issues
Read the following statements regarding Ahmed Khan's innovation in Bangalore:
I. Ahmed Khan developed Polyblend, a fine powder of recycled, modified plastic. II. This plastic powder is mixed with bitumen to lay roads. III. Blends of Polyblend and bitumen enhance the water-repellent properties of bitumen. IV. Khan's technique has been proven to increase road life by a factor of ten.
Which of the statements given above are correct?
Ahmed Khan developed Polyblend from recycled plastic. Mixed with bitumen, it improves water repellence and road durability. However, the technology increases road life by about three times, not ten. Hence, Statement IV is incorrect.
Question 74 of 100
📘 CLASS XII
Environmental Issues
Consider the following statements about Ramesh Chandra Dagar's organic farm in Haryana:
I. Integrated organic farming is a cyclical, zero-waste procedure where waste products from one process are recycled as nutrients. II. His farm integrates bee-keeping, dairy management, water harvesting, composting, and agriculture. III. He uses chemical fertilizers in low, controlled doses to maintain crop yields. IV. He created the Haryana Kisan Welfare Club to help spread organic farming, which now has 5,000 members.
Which of the statements given above are correct?
Integrated organic farming is a zero-waste system where one component supports another. Ramesh Chandra Dagar's farm integrates multiple agricultural activities and avoids chemical fertilizers by using compost and manure. He also established the Haryana Kisan Welfare Club with around 5,000 members. Therefore, Statement III is incorrect.
Question 75 of 100
📘 CLASS XII
Environmental Issues
Read the following statements regarding radioactive waste and nuclear energy:
I. Initially, nuclear energy was hailed as a non-polluting way of generating electricity. II. Nuclear energy has inherent problems, including accidental leakage as occurred at Three Mile Island and Chernobyl. III. Radiation given off by nuclear waste is extremely damaging because it causes mutations at a very high rate. IV. The recommended method of disposal is burying shielded containers in rocks 500 meters deep below the earth's surface.
Which of the statements given above are correct?
All four statements are correct. Nuclear energy was initially viewed as a clean energy source but accidents such as Three Mile Island and Chernobyl highlighted its risks. Radioactive waste causes mutations and cancer, and the recommended disposal method is burial of shielded containers about 500 metres deep within stable rock formations.
Question 76 of 100
📘 CLASS XII
Environmental Issues
Consider the following statements regarding the Greenhouse Effect:
I. The Earth’s surface re-emits heat in the form of infrared radiation. II. Greenhouse gases absorb a major fraction of this infrared radiation and radiate it back. III. Carbon dioxide (CO2) and methane (CH4) are the only two gases responsible for global warming. IV. Without the greenhouse effect, the average temperature of the Earth's surface would be -18°C.
Which of the statements given above are correct?
Statement III is incorrect because besides CO2 and CH4, gases such as chlorofluorocarbons (CFCs) and nitrous oxide (N2O) also contribute to the greenhouse effect. The remaining statements correctly describe the natural greenhouse effect.
Question 77 of 100
📘 CLASS XII
Environmental Issues
Read the following statements regarding Ozone depletion in the stratosphere:
I. Good ozone is found in the stratosphere and acts as a shield absorbing harmful UV rays. II. Bad ozone is formed in the troposphere and harms plants and animals. III. Ozone thickness is measured in Dobson Units (DU). IV. The ozone layer absorbs all wavelengths of UV-A completely.
Which of the statements given above are correct?
Statement IV is incorrect because UV-A is not completely absorbed by the ozone layer. The ozone layer mainly absorbs UV-C and a large proportion of UV-B radiation.
Question 78 of 100
📘 CLASS XII
Environmental Issues
With reference to the harmful impacts of UV-B radiation, consider the following statements:
I. UV-B damages DNA directly, which can lead to mutations. II. It causes aging of skin, damage to skin cells, and various skin cancers. III. High doses of UV-B cause inflammation of the cornea, commonly known as snow-blindness. IV. UV-B exposure is completely harmless to the eyes of mammals as they have protective fluids.
Which of the statements given above are correct?
Statement IV is incorrect because UV-B damages the eyes and may cause inflammation of the cornea (snow blindness) and cataracts. Statements I, II and III are correct.
Question 79 of 100
📘 CLASS XII
Environmental Issues
Consider the following statements about the Montreal Protocol:
I. It is an international treaty signed in Canada to control ozone depletion. II. The treaty was signed in 1987 but became effective in 1989. III. It laid down separate, definite roadmaps for developed and developing countries. IV. Its primary goal is to control and reduce the emission of greenhouse gases like methane.
Which of the statements given above are correct?
Statement IV is incorrect because the Montreal Protocol aims to control ozone-depleting substances such as CFCs, not greenhouse gases like methane.
Question 80 of 100
📘 CLASS XII
Environmental Issues
Read the following statements regarding the global status of Deforestation:
I. Almost 40 percent of forests have been lost in the tropics. II. In temperate regions, only about 12 percent of forest cover has been lost. III. Deforestation refers to the conversion of forested areas to non-forested ones. IV. The present scenario of deforestation is highly stabilized with net positive gains in India.
Which of the statements given above are correct?
Statement II is incorrect because only about 1 percent of forests have been lost in temperate regions. Statement IV is also incorrect because deforestation remains a serious concern in India.