Environmental Issues (Class 12)

MHT-CET के लिए Environmental Issues (Class 12) पर 2 अभ्यास प्रश्न, उत्तर सहित

Shishya के अभ्यास प्रश्न, AI से लिखे गए। हर उत्तर की जाँच एक स्वचालित दूसरी जाँच ने की है, किसी व्यक्ति ने नहीं।

1. 1.Which of the following gases is primarily responsible for the greenhouse effect leading to global warming?

   • (A)Nitrogen
   • (B)Oxygen
   • (C)Carbon dioxide
   • (D)Argon
   उत्तर और हल देखें

   उत्तर: (C) Carbon dioxide

   हल: The greenhouse effect is caused by gases that trap heat in the Earth's atmosphere. Among the options given: Nitrogen (78% of atmosphere) and Oxygen (21%) are the major components but they are diatomic molecules that do not absorb infrared radiation significantly. Argon is an inert noble gas present in trace amounts and does not contribute to greenhouse effect. Carbon dioxide (CO2) is a greenhouse gas that absorbs and re-emits infrared radiation, trapping heat in the atmosphere. Increased CO2 from burning fossil fuels, deforestation, and industrial activities has intensified the greenhouse effect, leading to global warming. Other greenhouse gases include methane (CH4), nitrous oxide (N2O), water vapor, and CFCs, but among the given options, carbon dioxide is the correct answer.

   ग़लती बताएँ

2. 2.Catalytic converters in automobiles reduce air pollution by converting harmful gases into less harmful substances. Which of the following conversions takes place in a catalytic converter?

   • (A)Carbon monoxide and nitrogen oxides are converted to carbon dioxide and nitrogen gas
   • (B)Sulphur dioxide is converted to sulphur trioxide
   • (C)Carbon dioxide is converted to carbon monoxide
   • (D)Nitrogen gas is converted to nitrogen oxides
   उत्तर और हल देखें

   उत्तर: (A) Carbon monoxide and nitrogen oxides are converted to carbon dioxide and nitrogen gas

   हल: Catalytic converters are emission control devices fitted in the exhaust system of vehicles. They contain catalysts (usually platinum, palladium, and rhodium) that facilitate chemical reactions to reduce harmful emissions. The main conversions that occur are: 1. Carbon monoxide (CO) is oxidized to carbon dioxide (CO2): 2CO + O2 → 2CO2 2. Unburnt hydrocarbons are oxidized to CO2 and H2O 3. Nitrogen oxides (NOx) are reduced to nitrogen gas (N2): 2NO → N2 + O2 or 2NO2 → N2 + 2O2 Option A correctly describes these conversions - carbon monoxide and nitrogen oxides (both harmful) are converted to carbon dioxide and nitrogen gas (less harmful/harmless). Option B describes formation of acid rain precursor (incorrect direction). Option C describes reverse of what actually happens. Option D describes formation of pollutants, not reduction. Therefore, option A is correct.

   ग़लती बताएँ