Which one of the following is the main cause of the acid rains ?

[amp_mcq option1=”The Sun causes heating of upper layer of atmosphere.” option2=”The burning of fossil fuels releases oxides of carbon, nitrogen and sulphur in the atmosphere.” option3=”The electrical charges are produced due to friction amongst clouds.” option4=”The atmosphere of the Earth contains acids.” correct=”option2″]

This question was previously asked in

UPSC CAPF – 2023

Download PDF Attempt Online

The correct answer is B. Acid rain is primarily caused by emissions of sulfur dioxide ($\text{SO}_2$) and nitrogen oxides ($\text{NO}_\text{x}$) which react with water molecules, oxygen, and other chemicals in the atmosphere to form sulfuric and nitric acids.

– The main source of sulfur dioxide and nitrogen oxides is the burning of fossil fuels in power plants, vehicles, and industries.
– These oxides dissolve in atmospheric water to form acidic compounds, which then fall to the ground as acid rain, snow, fog, or dry particles (acid deposition).

While carbon oxides (like $\text{CO}_2$) contribute to atmospheric processes such as climate change and ocean acidification, they are not the primary drivers of *acid rain* in the sense of acidic precipitation formed from sulfur and nitrogen pollutants. Natural sources like volcanic eruptions and decaying vegetation also contribute small amounts of sulfur and nitrogen compounds, but anthropogenic sources, particularly the burning of fossil fuels, are the dominant cause of widespread acid rain.

More similar MCQ questions for Exam preparation:-