Tag: global environmental change

Questions Related to global environmental change

Ozone layer of upper atmosphere is being destroyed by

commercial applications global environmental change ozone and its depletion ozone layer ozone layer depletion and causes

  1. Chlorofluorocarbons

  2. $ { SO } _{ 2 } $

  3. Smog

  4. None of the above

Show answer
Correct Option: A
Explanation:
$ { CFC } _{ s } $ are widely used as refrigerants. $ { CFC } _{ s } $ discharged in the lower part of atmosphere move upward and reach stratosphere. In stratosphere, UV rays act on them releasing CI atoms. CI degrades ozone releasing molecular oxygen, with these atoms acting merely as catalysts; CI atoms are not consumed in the reaction. $ { CFC } _{ s } $ added to the stratosphere have permanent and continuing affects on ozone levels.
So, the correct answer is 'Chlorofluorocarbons'.

Ozone hole means

commercial applications global environmental change ozone and its depletion ozone layer ozone layer depletion and causes

  1. Hole in the stratosphere

  2. Same concentration of ozone

  3. Decrease in the concentration of ozone

  4. Increase in the concentration of ozone

Show answer
Correct Option: C
Explanation:

Ozone occurs in the concentration of up to 1 ppm in the stratosphere as compared to 0.5 ppm in the troposphere. Ozone is formed in the stratosphere from oxygen due to solar radiations. Maximum ozone concentration is found at a distance of 23 to 25 km above the equator and 11 to 16 km over poles. It is called as ozone layer or ozonosphere. 

Ozone protects the earth by filtering out ultra-violet radiations. The ozone layer has two variable holes, a larger over south pole or Antarctica and a minor one over the north pole. High speed jets usually fly in stratosphere causing depletion of ozone. A decrease in concentration of ozone is called as the ozone hole.

Formation of ozone hole is maximum over

commercial applications global environmental change ozone and its depletion ozone layer ozone layer depletion and causes

  1. India

  2. Antarctica

  3. Europe

  4. Africa

Show answer
Correct Option: B
Explanation:

The thickness of ozone over the poles changes with the seasons being lowest in polar spring and maximum in polar autumn. Ozone hole refers to the depletion in the concentration of ozone over a restricted area as spring time decline over Antarctica. Spring time depletion of ozone is due to the action of sunlight over pollutants, which release chemicals like chlorine, that destroy ozone.

Ozone hole means

commercial applications global environmental change ozone and its depletion ozone layer ozone layer depletion and causes

  1. Hole in the stratosphere

  2. Same concentration of ozone

  3. Decrease in concentration of ozone

  4. Increase in the concentration of ozone

Show answer
Correct Option: C

In atmosphere , Ozone hole refers to

commercial applications global environmental change ozone and its depletion ozone layer ozone layer depletion and causes

  1. A hole in ozone layer

  2. Decrease in ozone layer thickness in troposphere

  3. Decrease in thickness of ozone layer in stratosphere

  4. Increase in the thickness of ozone layer in troposphere

Show answer
Correct Option: C
Explanation:

The region of stratosphere, at an altitude of 16-50km over equator and at a slightly lower altitude elsewhere having a thick sheet of ozone is known as ozonosphere. Decline in the thickness of ozone layer over a restricted area is called ozone hole. It was first discovered over Antarctica in 1985 by Dr. Joe C. Farman and his colleagues in the British Antarctica surveys. Chlorofluorocarbons are mainly responsible for ozone depletion in the stratosphere. CFC's are used as coolants in refrigerators and air conditioners, as propellants, cleaning solvents. Once released into the atmosphere, CFC'S reach the stratosphere and produce active chlorine in the presence of UV radiations. These radicals through chain reaction destroy ozone by converting it into oxygen.

Thus, the correct answer is option C. 

The pollutant that causes hole in the ozone layer is

commercial applications global environmental change ozone and its depletion ozone layer ozone layer depletion and causes

  1. $SF _{6}$

  2. nitrousoxide

  3. $CFC _{s}$

  4. $PFC _{s}$

Show answer
Correct Option: C

'Ozone-hole' means

commercial applications global environmental change ozone and its depletion ozone layer ozone layer depletion and causes

  1. A large sized hole in the ozone layer

  2. Thinning of the ozone layer

  3. Small holes scattered in the ozone layer

  4. Thickening of ozone in the ozone layer

Show answer
Correct Option: B
Explanation:

Ozone layer is a region of concentration of ozone molecule. $O _3 (O _2+ O)$ in the earth's atmosphere. The layer lies in the stratosphere at an altitude of 18-50 kms. The ozone layer naturally Shields earth's life from the harmful effect of the Sun's ultraviolet radiations. A severe depletion of ozone (ozone hole) in a region of the ozone layer was found particularly over Antarctica.  The depletion is caused by chlorofluorocarbons and by other compounds like $CCI _4, CF _4$ etc. So, the correct answer is 'Thinning of the ozone layer'.

Ozone hole was first detected over

commercial applications global environmental change ozone and its depletion ozone layer ozone layer depletion and causes

  1. Antarctica

  2. Arctic circle

  3. Equator

  4. Polar region

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Correct Option: A

Ozone hole means 

commercial applications global environmental change ozone and its depletion ozone layer ozone layer depletion and causes

  1. A large sized in the stratosphere layer

  2. Thinning of the ozone layer at the poles

  3. Small holes scattered in the ozone layer

  4. Thickening of the ozone layer at the poles

Show answer
Correct Option: B
Explanation:

We know that surrounding the troposphere of earth, there is a layer of the stratosphere. It is made up of ozone molecules that are formed by the effect of UV rays in these areas. Due to excessive chlorofluorocarbon compounds, and emission of carbon dioxide, it is getting depleted. At the poles, it is constantly getting thinner and thinner. This is called the ozone hole. 

So, option B is the correct answer.

Depletion of ozone layer is noticed on 

commercial applications global environmental change ozone and its depletion ozone layer ozone layer depletion and causes

  1. America

  2. Asia

  3. Australia

  4. All over the earth

Show answer
Correct Option: D
Explanation:

Depletion of ozone layer is noticed all over the earth.
Ozone is destroyed by collisions with other atoms and molecules.