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

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

The Montreal Protocol refers to

• persistent organic pollutants

• global warming and climate change

• substances that deplete the ozone layer

• biosafety of genetically modified organisms.

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

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.

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.

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.

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

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

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