Assertion: UV radiation causes photodissociation of ozone into O2

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 Multiple Choice QuestionsMultiple Choice Questions

101.

Assertion : Pollution is always caused by human activities.

Reason : Pollution is not different from contamination.

  • If both assertion and reason are true and reason is the correct explanation of assertion

  • If both assertion and reason are true but reason is not the correct explanation of assertion

  • If assertion is true but reason is false

  • If both assertion and reason are false


102.

Assertion : Chlorofluorocarbons are responsible for ozone depletion.

Reason : Ozone level decreases by as much as 67% every year.

  • If both assertion and reason are true and reason is the correct explanation of assertion

  • If both assertion and reason are true but reason is not the correct explanation of assertion

  • If assertion is true but reason is false

  • If both assertion and reason are false


103.

The Montreal Protocol refers to

  • persistent organic pollutants

  • global warming and climate change

  • substances that deplete the ozone layer

  • biosafety of genetically modified organisms.


104.

Which one of the following statement pertaining to pollutants is correct?

  • DDT is a non-biodegradable pollutant

  • Excess fluoride in drinking water causes osteoporosis

  • Excess cadmium in drinking water causes black foot disease

  • Methylmercury in water may cause "Itai ltai" disease


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105.

Assertion: Deforestation is one main factor contributing to global warming.

Reason: Besides CO2, two other gases methane and CFCs are also included under green house gases.

  • If both assertion and reason are true and reason is the correct explanation of assertion

  • If both assertion and reason are true but reason is not the correct explanation of assertion

  • If assertion is true but reason is false

  • If both assertion and reason are false.


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106.

Assertion: UV radiation causes photodissociation of ozone into O2 and O3 thus causing damage to the stratospheric ozone layer.

Reason: Ozone hole is resulting in global warming and climate change.

  • If both assertion and reason are true and reason is the correct explanation of assertion

  • If both assertion and reason are true but reason is not the correct explanation of assertion

  • If assertion is true but reason is false

  • If both assertion and reason are false.


A.

If both assertion and reason are true and reason is the correct explanation of assertion

Stratosphere zone of earth's atmosphere contains a layer of ozone (O3) which prevents the earth surface from about 99% of incoming solar ultraviolet radiations. The primary chemicals responsible for ozone depletion are a group of chlorine containing compounds called chloroflourocarbons (CFCs) used as coolants in refrigerators and air conditioners and propellants for aerosol cans and foam blowing agents for insulation and packaging and also as solvents. After their release into troposphere CFCs go to stratosphere when these are broken down by ultraviolet radiations releasing chlorine or bromine which break O3 molecules into O2 and O.

Due to depletion of Olayer, higher levels of ultra violet rays reach earth surface. Depletion in the concentration of ozone over a restricted area is called ozone hole. Ozone depletions results in problems like skin cancer, cataract animals becoming blind, mutations, inhibiting photosynthesis, decreases in productivity. Decreased photosynthetic activity will increase depletion of O3 layer, higher levels of ultra violet rays reach earth surface. Depletion in the concentration of ozone over a restricted area is called ozone hole. Ozone depletions results in problems like skin cancer, cataract animals becoming blind, mutations, inhibiting photosynthesis, decreases in productivity.

Decreased photosynthetic activity will increase Oconcentration of the atmosphere resulting in global warming. Besides CFCs, nitrogen oxide and hydrocarbons are also responsible for O2 depletion concentration of the atmosphere resulting in global warming. Besides CFCs, nitrogen oxide and hydrocarbons are also responsible for O3 depletion


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107.

Assertion: The concentration of methane in the atmosphere has more than doubled in the last 250 years.

Reason: Wetlands and rice fields are the major sources of methane.

  • If both assertion and reason are true and reason is the correct explanation of assertion

  • If both assertion and reason are true but reason is not the correct explanation of assertion

  • If assertion is true but reason is false

  • If both assertion and reason are false.


108.

Assertion : A suspended particulate matter (SPM) is an important pollutant released by diesel vehicles.

Reason : Catalytic converters greatly reduce pollution caused by automobiles.

  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion

  • If both Assertion and Reason are true but the Reason is not the correct explanation of the assertion

  • If Assertion is true but Reason is false.

  • If both Assertion and Reason are false


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109.

Assertion : Methane component of green house gases contributing to global warming is about 20 percent.

Reason : Introduction of multi-point fuel injection engines in automobiles has decreased methane content in the exhausts.

  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion

  • If both Assertion and Reason are true but the Reason is not the correct explanation of the assertion

  • If Assertion is true but Reason is false

  • If both Assertion and Reason are false


110.

Nitrogen oxides produced from the emission of automobiles and power plants, are the source of fine air borne particles which lead to

  • photochemical smog

  • dry acid deposition

  • industrial smog

  • wet acid deposition


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