Tag: global environmental change

Questions Related to global environmental change

Ozone protects biosphere from high energy

commercial applications global environmental change causes of resource depletion causes of greenhouse effect ozone layer depletion

  1. Infra-red rays

  2. Ultraviolet rays

  3. X - rays

  4. Gamma rays

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Correct Option: B
Explanation:

The ozone layer is mainly found in the stratosphere. Ozone layer acts as a shield that absorbs ultraviolet radiation from the sun. UV rays are highly injurious to living organisms since DNA and proteins of living organisms preferentially absorb UV rays, and its high energy breaks the chemical bonds within these molecules. UV-B damages DNA and mutation may occur. It causes aging of the skin, damage to skin cells and various types of skin cancers.

Chlorofluorocarbon releases a chemical harmful to ozone

commercial applications global environmental change causes of resource depletion causes of greenhouse effect ozone layer depletion

  1. Fluorine

  2. Sulphur dioxide

  3. Nitrogen peroxide

  4. Chlorine

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Correct Option: D
Explanation:

Ozone gas is a layer which is present in the stratosphere and absorbs the harmful ultraviolet radiation. The ozone depletion takes due to the excessive emission of (CFCs). CFC find wide use as refrigerants. CFCs discharged in the lower part of atmosphere move upward and reach stratosphere. In stratosphere, UV rays act on them releasing Cl atoms. Cl degrades ozone releasing molecular oxygen, with these atoms acting merely as catalysts; Cl atoms are not consumed in the reaction. Hence, whatever CFCs are added to the stratosphere, they have permanent and continuing affects on ozone levels. This has resulted in formation of a large area of thinned ozone layer, commonly called as the ozone hole.

Therefore, the correct answer is option D.

Ozone layer is disturbed by

commercial applications global environmental change causes of resource depletion causes of greenhouse effect ozone layer depletion

  1. Large number of factories

  2. Supersonic jets

  3. Large number of automobiles

  4. None of these

Show answer
Correct Option: B
Explanation:
Ozone is a form of a blanket covering the upper atmosphere which protects the earth from harmful ultraviolet rays. Because of ozone depletion, these rays can now reach the earth through hole which was previously protected by ozone blanket. The various causes of ozone depletion are as follows:
  • Huge combustion of fossil fuel and organic matter.
  • Excessive use of nitrogenous fertilizers.
  • supersonic rockets and space shutters.
  • Nuclear test.
  • Excessive use of chlorofluorocarbons.
So, the correct answer is option B.

The common refrigerant chlorofluoromethane (freon) and NO$ _x$ is a serious pollutant because

commercial applications global environmental change causes of resource depletion causes of greenhouse effect ozone layer depletion

  1. It destroys haemoglobin

  2. It disrupts O$ _3$ layer

  3. It lowers atmospheric temperature

  4. It prevents cloud condensation

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Correct Option: B

CFCs used in refrigerators cause 

commercial applications global environmental change causes of resource depletion causes of greenhouse effect ozone layer depletion

  1. Water pollution

  2. Ozone depletion

  3. Acid rain

  4. Photochemical smog

Show answer
Correct Option: B
Explanation:

The presence of CFCs in the atmosphere results in the depletion of the ozone layer. They are used as coolants in refrigerators, coolers, etc. The CFCs causes the breaking of the ozone molecule which forms the oxygen radical and O$ _2$. The depletion of the ozone layer results in the penetration of the harmful UV radiations from the sun into the Earth's atmosphere. 

Thus, the correct answer is option B. 

Which of the following chemical is released by chlorofluorocarbon that is harmful to ozone ?
commercial applications global environmental change causes of resource depletion causes of greenhouse effect ozone layer depletion

  1. Fluorine

  2. Sulphur dioxide

  3. Nitrogen peroxide

  4. Chlorine

Show answer
Correct Option: D
Explanation:

Chlorofluorocarbons are the compounds which are used as coolants in the air conditioning systems, refrigerators, coolers, etc. The CFCs, when released into the atmosphere, react with UV rays to form chlorine atoms which destroy the ozone layer and results in the thinning out of the ozone layer also known as the ozone hole.

Thus, the correct answer is option D. 

Increase skin cancer and higher mutation rates are generally the consequences of

commercial applications global environmental change causes of resource depletion causes of greenhouse effect ozone layer depletion

  1. CO$ _2$

  2. Ozone depletion

  3. Biomagnification

  4. Acid rains

Show answer
Correct Option: B
Explanation:

The ozone layer is present in the stratosphere above the Earth. The layer of ozone is responsible for the absorption of the harmful ultraviolet radiations from the solar radiations. Due to ozone depletion, these radiations enter the Earth's atmosphere and cause skin cancer. The radiations can also damage the eye and other exposed parts of the body. The radiations can also cause mutations like thymine dimer formation or breaking of the hydrogen bonds. 

Thus, the correct answer is option B. 

The factor responsible for depletion of ozone layer is

commercial applications global environmental change causes of resource depletion causes of greenhouse effect ozone layer depletion

  1. Excessive use of automobiles

  2. Excessive industrial units

  3. Excessive use of man made compounds containing chlorine and fluorine

  4. Excessive deforestation

Show answer
Correct Option: C
Explanation:

Chlorofluorocarbon compounds are released from automobiles, refrigerators, etc. These compounds cause an increase in atmospheric temperature causing global warming.

So, option C " Excessive use of man-made compounds containing chlorine and fluorine" is the correct answer.

The ozone layer: Between 15 and 50 km above the earth is a thin layer of gas called 'ozone'. It protects the earth from most of the sun's harmful ultraviolet radiation. Too much radiation causes blindness in animals and skin cancer in people. In 1985, scientists discovered a hole in the ozone layer in the Antartica. They have recently discovered a smaller hole over the arctic. The ozone layer is also becoming thinner over other locations of the earth too. Scientists believe that over the last 10 years about 30% of the ozone layer has disappeared. This damage is caused by chemicals. Choose the right statement(s) from the following. 

commercial applications global environmental change causes of resource depletion causes of greenhouse effect ozone layer depletion

  1. The greenhouse effect would be more efficient and the temperature of earth would increase.

  2. CFCs would result in the depletion of the ozone layer.

  3. Infrared radiation from the sun would bombard earth.

  4. Ultraviolet radiation from the sun cannot enter earth.

Show answer
Correct Option: B
Explanation:

The presence of CFCs in the atmosphere results in the depletion of the ozone layer. They are used as coolants in refrigerators, coolers, etc. The CFCs causes the breaking of the ozone molecule which forms the oxygen radical and O$ _2$. The depletion of the ozone layer results in the penetration of the harmful UV radiations from the sun into the Earth's atmosphere. 

Thus, the correct answer is option B. 

Ozone is found in the atmosphere and helps to protect us from harmful radiation. Ozone is

commercial applications global environmental change causes of resource depletion causes of greenhouse effect ozone layer depletion

  1. $\displaystyle { O }^{ 2- }$

  2. $\displaystyle { O }^{ - }$

  3. $\displaystyle \ { O } _{ 2 }\ $

  4. $\displaystyle \ { O } _{ 3 }\ $

Show answer
Correct Option: D
Explanation:

Ozone is an inorganic molecule formed by the three molecules of oxygen with the chemical formula O$ _3$. It is a pale blue gas with a distinctively pungent smell. It is an allotrope of oxygen that is much less stable than the diatomic allotrope O$ _2$ and more reactive molecule.