Tag: causes of resource depletion

Questions Related to causes of resource depletion

What happen when the destruction of the ozone layer increases?

  1. The amount of harmful ultraviolet radiation

  2. The amount of needful ultraviolet radiation

  3. The amount of ultra radiations

  4. None of these


Correct Option: A
Explanation:

When the destruction of the ozone layer increases, the amount of harmful ultraviolet radiation increases.
Note:
Ozone layer acts as natural sun block and shields us from the UV radiations of the sun which are dangerous to living organisms.
The ozone molecules absorb ultraviolet rays between 310 to 200 nm wavelength.
Ozone absorbs UV radiation to give back oxygen. Thus, the ozone layer acts as a screen and prevents the harmful radiations from reaching the surface of earth.

Ozone is present as a chief constituent in which region of the atmosphere?

  1. Troposphere

  2. Stratosphere

  3. Mesosphere

  4. Thermosphere


Correct Option: B
Explanation:
The stratosphere is a second layer of Earth's atmosphere. The troposphere, the lowest layer, is right below the stratosphere. The next higher layer above the stratosphere is the mesosphere.
Ozone is a three oxygen molecule that are abundant in the stratosphere, it absorbs energy from incoming ultraviolet radiation from the Sun. 

Identify the harmful radiations emitted by the sun.

  1. Ultra violet

  2. Infra red

  3. Visible

  4. Radio waves


Correct Option: A
Explanation:

The ultraviolet radiations are the harmful rays which are present in the sun rays. The radiations are emitted from the sun and are harmful to living organisms. The ozone layer prevents the entry of these radiations into the Earth's atmosphere. The depletion of the ozone layer allows the radiations to cause harm to the plants and animals on the Earth.

Thus, the correct answer is option A. 

The reduction in the amount of chlorofluorocarbons (CFCs) released into the air has had the greatest positive effect upon 

  1. Water pollution 

  2. Noise pollution

  3. Acid rain 

  4. The ozone layer

  5. Endangered species


Correct Option: D
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. The reduction in the use of the CFC molecules will prevent the ozone thinning and have the positive effect on the ozone layer. 

Thus, the correct answer is option D. 

The stratospheric ozone depletion leads to

  1. Global warming

  2. Increase in the incidence of skin cancers

  3. Forest fires

  4. All of the above


Correct Option: D
Explanation:
Thinning of ozone layer increases the amount of UV-B radiations reaching the earth. This may lead to incidences of cataract, skin cancers, photo burning etc. Decreased photosynthetic activity will increase carbon dioxide concentration of the atmosphere resulting in global warming. Increased exposure of radiations may also lead to forest fires especially during dry summers.
So, the correct answer is 'All of the above'

In coming years, skin related disorders will be more common due to:

  1. Pollutants in air

  2. Use of detergents

  3. Water pollution

  4. Depletion of ozone layer


Correct Option: D
Explanation:

Thinning of ozone layer increases the amount of ultraviolet radiations reaching the earth surface. The increased UV-B radiation increases incidence of cataract, skin cancers herpes, dimming of eyesight, photo burning, snow blindness and deficient functioning of immune system. 

Of the following, which is a greenhouse gas?

  1. Nitrogen dioxide

  2. Sulphur dioxide

  3. Carbon dioxide

  4. Carbon monoxide


Correct Option: C
Explanation:
Greenhouse gases generally traps the radiations of the earth which leads to increase in the temperature of the earth and is the major cause for global warming. The greenhouse gases includes water vapour, carbon dioxide, methane, nitrous oxide, and ozone.
Thus, the correct answer is option C.

Freon gas causing stratosphere $O _3$ depletion is mainly released from

  1. Refrigerators

  2. Automobiles

  3. Thermal power plants

  4. Steel industry


Correct Option: A
Explanation:
Freon gas is a type of chlorofluorocarbon (CFC) i.e., it contains carbon and hydrogen along with fluorine and chlorine. It is used as a refrigerant. CFCs release chlorine atoms in the atmosphere that react with ozone and cause its depletion. Hence, Freon causes ozone depletion and it is released from refrigerators.
So, the correct answer is 'Refrigerators'.

Maximum ozone depletion is caused by

  1. $CO _2$

  2. CFC

  3. $SO _2$

  4. $CH _4$


Correct Option: B
Explanation:
The primary cause for ozone depletion are CFCs. CFCs or Chlorofluorocarbons are the compounds that contain carbon and hydrogen along with chlorine and fluorine. They are used as refrigerants and in air conditioners. CFCs release chlorine radicals that react with ozone and cause its degradation. The mechanism of ozone depletion by CFC is as follows:
              UV- C
CFCl3 ----------------> CFCl2 + Cl
               UV-C
CFCl2 -----------------> CFCl + Cl
Cl + O3 ----------------> ClO + O2
ClO + O3 --------------> Cl + 2O2
Hence, CFC causes degradation of ozone. Also, the chlorine atom remains in the atmosphere and reacts with another molecule of ozone.
So, the correct answer is 'CFC'.

Excessive exposure of humans to UV-rays results in

  1. damage to immune system

  2. damage to lungs

  3. skin cancer

  4. peptic ulcers


Correct Option: A,C
Explanation:
UV rays or ultraviolet rays can affect human health in many ways like causing skin cancer and a weakening immune system. Excessive exposure to UV rays can lead to skin cancer because the UV rays cause damage to the DNA in skin cells. UV rays also affect the distribution and activity of cells that trigger immune responses thus, making the immune system weak. UV rays first affect the skin and the whole body.
So, the correct answer is option A and C i.e. 'damage to immune system' and 'skin cancer'.