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100 questions in this collection · Page 9 of 10
Question 81 of 100
📘 CLASS XII
Environmental Issues
Regarding India's historical forest cover and forest policy, consider the following statements:
I. At the beginning of the twentieth century, forests covered about 30 percent of India's land. II. By the end of the twentieth century, forest cover had shrunk to 21.54 percent. III. The National Forest Policy (1988) recommends 33 percent forest cover for the plains. IV. The National Forest Policy (1988) recommends 80 percent forest cover for the hills to prevent landslides.
Which of the statements given above are correct?
Statement IV is incorrect because the National Forest Policy recommends 67 percent forest cover in hills and 33 percent in plains.
Question 82 of 100
📘 CLASS XII
Environmental Issues
Analyze the following statements about "Slash and Burn" agriculture (Jhum Cultivation):
I. It is widely practiced in the north-eastern states of India. II. The ash from burning forest trees is used as natural fertilizer. III. The land is farmed and then left barren for a recovery phase of several years. IV. Due to population growth, the recovery phase has been significantly lengthened to allow better soil enrichment.
Which of the statements given above are correct?
Statement IV is incorrect because increasing population pressure has shortened the fallow period, preventing adequate recovery of soil fertility.
Question 83 of 100
📘 CLASS XII
Environmental Issues
With reference to the historic sacrifice of Amrita Devi Bishnoi, read the following statements:
I. In 1731, the King of Jodhpur, Rajasthan, ordered trees to be cut down for his new palace. II. Amrita Devi Bishnoi and her daughters hugged the trees to protect them from the king's men. III. They lost their lives along with hundreds of other Bishnois during this conservation struggle. IV. The Government of India instituted an award in her name for exemplary bravery shown by urban industrial developers.
Which of the statements given above are correct?
Statement IV is incorrect because the Amrita Devi Bishnoi Wildlife Protection Award recognizes rural individuals and communities showing exceptional courage in wildlife protection.
Question 84 of 100
📘 CLASS XII
Environmental Issues
Consider the following statements about the Chipko Movement and Joint Forest Management (JFM):
I. The Chipko Movement started in 1974 in the Garhwal Himalayas. II. Local women played a key role by hugging trees to prevent contractors from felling them. III. Recognizing the value of local participation, the Government of India introduced Joint Forest Management (JFM) in the 1980s. IV. Under JFM, local communities manage forests and get absolute ownership of land in return.
Which of the statements given above are correct?
Statement IV is incorrect because Joint Forest Management does not transfer land ownership. Communities participate in forest protection and receive benefits such as fruits, gum, medicines and other forest produce.
Question 85 of 100
📘 CLASS XII
Environmental Issues
Read the following statements regarding the CPCB regulations on air pollutants:
I. The Central Pollution Control Board (CPCB) is the regulatory authority in India. II. PM 2.5 refers to particulate matter of size 2.5 micrometers or less in diameter. III. PM 2.5 causes minor, temporary sneezing but is completely filtered out by nasal hairs. IV. These fine particles can be inhaled deep into the lungs, leading to respiratory symptoms and premature deaths.
Which of the statements given above are correct?
Statement III is incorrect because PM 2.5 particles are small enough to bypass the nasal hairs and penetrate deep into the lungs, causing inflammation, respiratory disorders and premature deaths.
Question 86 of 100
📘 CLASS XII
Environmental Issues
With reference to the Electrostatic Precipitator, consider the following statements:
I. It can remove more than 99% of particulate matter from power plant emissions. II. It uses electrode wires at thousands of volts to produce a corona. III. The corona releases electrons that give dust particles a negative charge. IV. The collecting plates are positively charged to attract the negative dust.
Which of the statements given above are correct?
Statement IV is incorrect because the collecting plates are grounded, not positively charged. Negatively charged dust particles are attracted to the grounded collecting plates and settle due to gravity.
Question 87 of 100
📘 CLASS XII
Environmental Issues
Consider the following statements regarding Catalytic Converters:
I. They use expensive catalysts: platinum, palladium, and rhodium. II. They change nitric oxide into nitrogen and oxygen gases. III. They oxidize carbon monoxide into carbon dioxide. IV. Unleaded petrol must be used to avoid inactivating the metal catalysts.
Which of the statements given above are correct?
All four statements are correct. Catalytic converters use platinum, palladium and rhodium to convert nitric oxide into nitrogen and oxygen, carbon monoxide into carbon dioxide, and hydrocarbons into carbon dioxide and water. Unleaded petrol is essential because lead poisons the catalysts.
Question 88 of 100
📘 CLASS XII
Environmental Issues
Read the following statements regarding Noise Pollution legislation:
I. In India, noise was included as an air pollutant in the Air Act in 1987. II. Brief exposure to sound levels of 150 dB or more can permanently damage hearing. III. Chronic exposure to relatively lower noise levels in cities does not cause any physiological harm. IV. Noise pollution can cause sleeplessness, high heart rates, and altered breathing patterns.
Which of the statements given above are correct?
Statement III is incorrect because prolonged exposure to even relatively lower noise levels can cause hearing impairment, stress, sleeplessness, hypertension, increased heart rate and altered breathing patterns.
Question 89 of 100
📘 CLASS XII
Environmental Issues
Regarding Delhi's switch to CNG, read the following statements:
I. By the end of 2002, all public transport buses in Delhi were shifted to run on CNG. II. CNG burns more efficiently than diesel or petrol. III. CNG is cheaper than diesel, and its main advantage is that it can easily be adulterated with liquid fuels. IV. The primary challenge of CNG is setting up pipelines for uninterrupted distribution.
Which of the statements given above are correct?
Statement III is incorrect because CNG cannot be siphoned off or adulterated, making it a cleaner and safer fuel. Statements I, II and IV are correct.
Question 90 of 100
📘 CLASS XII
Environmental Issues
With reference to the composition of domestic sewage, consider the following statements:
I. Domestic sewage contains a mere 0.1 percent of impurities. II. Suspended solids include nitrates, phosphates, and calcium. III. Colloidal materials include bacteria, paper fibers, and fecal matter. IV. Dissolved materials include plant nutrients and salts.
Which of the statements given above are correct?
Statement II is incorrect because nitrates, phosphates and calcium are dissolved substances. Suspended solids mainly include sand, silt and clay, while colloidal materials include bacteria, paper fibres and fecal matter.