Tag: depletion of ozone layer

Questions Related to depletion of ozone layer

Greenhouse effect is due to

  1. accumulation of $ { O } _{ 3 } $ and depletion of $ { CO } _{ 2 } $

  2. accumulation of both $ { O } _{ 3 } $ and $ { CO } _{ 2 } $

  3. accumulation of $ { CO } _{ 2 } $ and depletion of $ { O } _{ 3 } $

  4. presence of green plants on the Earth.


Correct Option: C
Explanation:
Greenhouse effect, a warming of Earth’s surface and troposphere (the lowest layer of the atmosphere) is caused by the presence of water vapour, carbon dioxide, methane, and certain other gases in the air. Of those gases, known as greenhouse gases, water vapour has the largest effect. The atmosphere allows most of the visible light from the Sun to pass through and reach Earth’s surface. As Earth’s surface is heated by sunlight, it radiates part of this energy back toward space as infrared radiation. This radiation, unlike visible light, tends to be absorbed by the greenhouse gases in the atmosphere, raising its temperature. The heated atmosphere in turn radiates infrared radiation back toward Earth’s surface. 
So the correct option is 'accumulation of CO$ _2$ and depletion of O$ _3$'.

Read the given statements and select the correct option.


Statement 1: The average temperature of Earth has increased by $ 0.6 $ during the past century.
Statement 2: There has been a progressive increase in the use of fossil fuels generating more greenhouse gases.

  1. Both statements 1 and 2 are correct.

  2. Statement 1 is correct but statement 2 is incorrect.

  3. Statement 1 is incorrect but statement 2 is correct.

  4. Both statements 1 and 2 are incorrect.


Correct Option: A
Explanation:

The various greenhouse gases are $ { CO } _{ 2 }, { CH } _{ 4 }, { CFC } _{ s } $ and $ { N } _{ 2 }{ O } $. Excessive use of fossil fuel is adding more $ { CO } _{ 2 } $ to atmosphere. This increase in concentration of greenhouse gases has led to considerable heating of earth leading to global warming. During the pas century, the temperature of earth has increased by $ 0.6 $.

Identify the incorrect statement from the following

  1. Oxides of nitrogen in the atmosphere can cause the depletion of ozone layer

  2. Ozone absorbs the intense ultraviolet radiations of the sun

  3. Depletion of ozone layer is because of its chemical reactions with  CFC

  4. Ozone absorbs infrared radiations


Correct Option: D
Explanation:

Ozone doesn't absorb infrared radiation , it absorbs ultraviolet radiations .

Which of the following is not a greenhouse gas?

  1. Methane $CH _4$

  2. Ozone $O _3$

  3. Oxygen $O _2$

  4. Carbon dioxide $CO _2$


Correct Option: C
Explanation:

Oxygen is not greenhouse gas, because they are transparent to infrared light.

In absence of Green House Gases, the temperature of Earth shall fall down to ___

  1. -18 degree Celcius

  2. -15 degree Celcius

  3. -20 degree Celcius

  4. -10 degree Celcius


Correct Option: A
Explanation:

Because Green House Gases are responsible to trap heat in earth surface. If green house gases are absent, the temperature of Earth shall fall down to -18 degree Celcius

So, the correct answer is '-18$^0$

Correct percentage of two green house gases is

  1. $N _2O-6\%, CO _2-86\%$

  2. $CH _4-20\%, N _2O-18\%$

  3. $CO _2-40\%, CFC-30\%$

  4. $CFC-14\%, CH _4-20\%$


Correct Option: D
Explanation:
The warming of earth's surface when sun radiations are absorbed and trapped in earth's atmosphere, is called greenhouse effect. The gases responsible for green house effect are called green house gases which trap the radiations and don't let them reflect back from the earth's surface. The green house gases are Chlorofluorocarbons (CFC's), Carbon dioxide (CO2), Methane (CH4) and Nitrous Oxide (N2O). 
The approximate percentage of different greenhouse gases in the atmosphere is:
CFCs - 14%
CO2 - 60%
‎CH4 - 20%
N2O - 6%
So, the correct answer is 'CFC14%, CH4 - 20%

Which of the following is a green house gas?

  1. Methane

  2. CO

  3. Water vapour

  4. Oxygen


Correct Option: A
Explanation:
The warming of earth's surface when sun radiations are absorbed and trapped in earth's atmosphere, is called greenhouse effect. The gases responsible for green house effect are called green house gases which trap the radiations and don't let them reflect back from the earth's surface. The green house gases are Chlorofluorocarbons (CFCs), Carbon dioxide (CO2), Methane (CH4) and Nitrous Oxide (N2O). 
So, the correct answer is 'Methane'.

Carbon dioxide is called a green house gas because

  1. It emits light

  2. It traps infra red radiations

  3. It traps ultraviolet radiations

  4. It is involved in photosynthesis


Correct Option: B
Explanation:
The warming of earth's surface when sun radiations are absorbed and trapped in earth's atmosphere, is called greenhouse effect. The gases responsible for green house effect are called green house gases which trap the radiations and don't let them reflect back from the earth's surface. Carbon dioxide traps the infra red radiations and accounts for greatest contribution to greenhouse effect.
So, the correct answer is 'It traps infra red radiations'.

Which greenhouse gas contributes 20% to global warming?

  1. Methane

  2. N$ _2$O

  3. CFCs

  4. CO$ _2$


Correct Option: A
Explanation:
he gases responsible for green house effect are called green house gases which trap the radiations and don't let them reflect back from the earth's surface. The green house gases are Chlorofluorocarbons (CFC's), Carbon dioxide (CO2), Methane (CH4) and Nitrous Oxide (N2O). 
The approximate percentage of different greenhouse gases in the atmosphere is:
CFCs - 14%
CO2 - 60%
‎CH4 - 20%
N2O - 6%
So, the correct answer is 'Methane'.

Earth is kept warm due to green house flux.

  1. True

  2. False


Correct Option: A
Explanation:
Greenhouse flux occurs due to the accumulation of greenhouse gases. Gases like carbon dioxide, methane, nitrous oxide trap radiations and absorb the light. The energy gets trapped in the earth and this causes a rise in temperature of the earth causing it to become warmer. This is called the greenhouse effect. Carbon dioxide has a maximum contribution in the greenhouse effect. It also maintains optimum earth temperature as less concentration of carbon dioxide will lead to loss of heat from earth causing a decrease in temperature. However, excess concentration of carbon dioxide can lead to an increase in earth's temperature causing global warming.
Hence, the statement given in the question is correct.
So, the correct answer is 'True'.