Which one of the following is the main cause of the acid rains ?
- A.The Sun causes heating of upper layer of atmosphere.
- B.The burning of fossil fuels releases oxides of carbon, nitrogen and sulphur in the atmosphere.
- C.The electrical charges are produced due to friction amongst clouds.
- D.The atmosphere of the Earth contains acids.
Correct answer
Explanation
The correct answer is B. Burning coal, petrol and diesel releases oxides of sulphur and nitrogen (and carbon), which dissolve in rain water to form acids.
Sulphur dioxide from thermal power plants and smelters forms sulphuric acid, and nitrogen oxides from vehicle engines and furnaces form nitric acid. Normal rain is slightly acidic, with a pH of about 5.6, because carbon dioxide forms weak carbonic acid; rain with a pH below 5.6 is called acid rain. It damages forests, makes lakes too acidic for fish, leaches nutrients from soil and corrodes marble and metal. The yellowing of the marble of the Taj Mahal, blamed partly on the Mathura refinery, is the standard Indian example.
A is wrong: heating of the upper atmosphere by the Sun does not make rain acidic.
C is wrong: lightning fixes a little nitrogen, but it is a minor natural source, not the main cause.
D is wrong: the atmosphere does not naturally contain acids; they form from pollutant gases.
Exam tip: Acid rain = SO₂ and NOₓ from fossil fuels; pH below 5.6; Taj Mahal "marble cancer".
Practice Questions
View allConsider the following :
1. Battery storage
2. Biomass generators
3. Fuel cells
4. Rooftop solar photovoltaic units
How many of the above are considered "Distributed Energy Resources"?
- A.Only one
- B.Only two
- C.Only three
- D.All four
Show answer
Battery storage, biomass generators, fuel cells and rooftop solar units are all small, local sources that generate or store power close to where it is used, which is what Distributed Energy Resources are.
Read the full explanation →Due to some reasons, if there is a huge fall in the population of species of butterflies, what could be its likely consequence/consequences ?
1. Pollination of some plants could be adversely affected.
2. There could be a drastic increase in the fungal infections of some cultivated plants.
3. It could lead to a fall in the population of some species of wasps, spiders and birds.
Select the correct answer using the code given below :
- A.1 only
- B.2 and 3 only
- C.1 and 3 only
- D.1, 2 and 3
Show answer
Butterflies are pollinators and also food for many animals, so their decline would hurt pollination and their predators; it has no direct link with fungal diseases of crops.
Read the full explanation →Consider the following statements :
1. Lions do not have a particular breeding season.
2. Unlike most other big cats, cheetahs do not roar.
3. Unlike male lions, male leopards do not proclaim their territory by scent marking.
Which of the statements given above are correct ?
- A.1 and 2 only
- B.2 and 3 only
- C.1 and 3 only
- D.1, 2 and 3
Show answer
Lions breed at any time of year and cheetahs cannot roar, but male leopards do mark their territory with scent.
Read the full explanation →Which one of the following National Parks lies completely in the temperate alpine zone?
- A.Manas National Park
- B.Namdapha National Park
- C.Neora Valley National Park
- D.Valley of Flowers National Park
Show answer
Set high in the Garhwal Himalaya of Uttarakhand, roughly between 3,200 and 6,600 metres, it lies wholly in the temperate alpine zone.
Read the full explanation →Consider the following kinds of organisms:
1. Copepods
2. Cyanobacteria
3. Diatoms
4. Foraminifera
Which of the above are primary producers in the food chains of oceans?
- A.1 and 2
- B.2 and 3
- C.3 and 4
- D.1 and 4
Show answer
Cyanobacteria and diatoms carry out photosynthesis, so they are phytoplankton, the primary producers at the base of ocean food chains.
Read the full explanation →