Tag: water and air and their importance

Questions Related to water and air and their importance

Cutting down forests and using the land for other purposes is known as deforestation. It has adverse effects on the environment. Which of the following are correct regarding these effects? 
(i) Decrease in soil erosion  (ii) Increase in temperature (iii) Ground water level gets lowered (iv) Droughts and floods (v) Increase in water holding capacity of the soil

  1. (i), (ii), (iii) & (iv)

  2. (ii), (iv) & (v)

  3. (ii), (iii) & (iv)

  4. (i), (ii), (iv) & (v)


Correct Option: C
Explanation:

Deforestation is the permanent destruction of forests in order to make the land available for other uses.
effects of deforestation:
Forests are complex ecosystems that affect almost every species on the planet. When they are degraded, it can set off a devastating chain of events both locally and around the world.
Loss of species: 
Seventy percent of the worlds plants and animals live in forests and are losing their habitats to deforestation, according to National Geographic. Loss of habitat can lead to species extinction. It also has negative consequences for medicinal research and local populations who rely on the animals and plants in the forests for hunting and medicine.
Water cycle: 
Trees are important to the water cycle. They absorb rain fall and produce water vapor that is released into the atmosphere. Trees also lessen the pollution in water, according to the North Carolina State University, by stopping polluted runoff. In the Amazon, more than half the water in the ecosystem is held within the plants, according to the National Geographic Society. 
Soil erosion: 
Tree roots anchor the soil. Without trees, the soil is free to wash or blow away, which can lead to vegetation growth problems. The WWF states that scientists estimate that a third of the worlds arable land has been lost to deforestation since 1960. After a clear cutting, cash crops like coffee, soy and palm oil are planted. Planting these types of trees can cause further soil erosion because their roots cannot hold onto the soil. "The situation in Haiti compared to the Dominican Republic is a great example of the important role forests play in the water cycle," Daley said. Both countries share the same island, but Haiti has much less forest cover than the Dominican Republic. As a result, Haiti has endured more extreme soil erosion, flooding and landslide issues.
Life quality: Soil erosion can also lead to silt entering the lakes, streams and other water sources. This can decrease local water quality and contribute to poor health in populations in the area.

_________  is the man-made cause of deforestation.

  1. Urbanization

  2. Forest Fire

  3. Droughts

  4. All of the above


Correct Option: A
Explanation:

Urbanization is the man-made cause of deforestation. Whereas forest fires and droughts are natural causes of deforestation.
Urbanization is due to increase population. It is caused due to human activities. Urbanization decreases the area under forests which leads to reduction in the number of CO2 consuming trees. Hence, CO2 accumulates in the air.

The significant natural causes of air pollution are:

  1. volcanic eruptions

  2. forest fires

  3.  both A and B both

  4. none of the above


Correct Option: C
Explanation:

The significant natural causes of air pollution are volcanic eruptions and forest fires.

The major causes of man-made air pollution are: 

  1. burning oil

  2. coal

  3. gasoline

  4. all of the above


Correct Option: D
Explanation:

Burning oil, coal, gasoline and other fossil fuels are the major causes of man-made air pollution.

All forest fires emit(s):

  1. carbon monoxide

  2. sulphur dioxide

  3. nitrogen dioxide

  4. all of the above


Correct Option: D
Explanation:

All forest fires emit carbon monoxide, sulphur dioxide, nitrogen dioxide, ozone, and particulate matter.

Which of the following is not a source of air pollution?

  1. Automobile exhaust

  2. Burning of firewood

  3. Windmill

  4. Power plant


Correct Option: C
Explanation:

Windmill are used to produce energy by the motion of wind, it is a renewable source of energy and does not cause air pollution.

Match column I with column II and pick the correct option from the codes given below:

Column I Column II
p. Peroxy acetyl nitrate 1. Waste incineration
q. Polycyclic aromatic hydrocarbons 2. Global warming
r. Dioxins 3. Photochemical smog
s. Indigo 4. Carcinogens
t. IR active molecules 5. Vat dye
  1. p-3, q-4, r-1, s-5, t-2

  2. p-1, q-2, r-3, s-4, t-5

  3. p-3, q-5, r-1, s-2, t-4

  4. p-5, q-3, r-1, s-2, t-4


Correct Option: A

Which among the given is not a natural source of air pollution?

  1. Automobile exhausts

  2. Vegetation decay

  3. Forest fire

  4. Volcanic eruptions


Correct Option: A
Explanation:
The automobile exhaustion is not a natural source of air pollution, it is man-made air pollution.
It is emitted as a result of the combustion of fuels such as natural gas, gasoline, petrol,bio-diesel etc. It discharges a large amount of $CO _2$(carbon dioxide), NO, CO, ozone etc.

Hence, the correct option is A.

Which of the following applications reveal that nitrogen is inert?

  1. Tinned food products

  2. Making of fertilizers

  3. Refrigerant

  4. Electric bulbs


Correct Option: A,D
Explanation:

Usage of nitrogen in tinned food products, in electric bulbs and as a refrigerant indicating the inactive nature of nitrogen.

The component of air essential for growth of plants and animals is ________.

  1. oxygen

  2. nitrogen

  3. hydrogen

  4. argon


Correct Option: B
Explanation:

The component of air which is essential for growth of plants and animals is nitrogen. Atmospheric nitrogen is converted by bacteria through nitrogen fixation to nitrate and nitrites, which is consumed by plants. Animals also need nitrogen, as all amino acids which are the building blocks of proteins have basic element of nitrogen.