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Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Photochemical smog causes cracking of rubber.
Reason (R): Presence of ozone, nitric oxide, acrolein, formaldehyde and peroxyacetyl nitrate in photochemical smog makes it oxidizing.
Choose the most appropriate answer from the options given below:

BOD values (in ppm) for clean water \( (A) \) and polluted water \( (B) \) are expected respectively as:

Match List I and List II

Choose the correct answer from the options given below:

The green house gas/es is (are):
(A) Carbon dioxide (B) Oxygen (C) Water vapour (D) Methane
Choose the most appropriate answer from the options given below:

In stratosphere most of the ozone formation is assisted by :

The gas 'A' is having very low reactivity reaches to stratosphere. It is non-toxic and non-flammable but dissociated by UV-radiations in stratosphere. The intermediates formed initially from the gas 'A' are:

Water sample is called cleanest on the basis of which one of the BOD value given below.

Reducing smog is a mixture of :

The deposition of \( X \) and \( Y \) on ground surfaces is referred as wet and dry depositions, respectively. \( X \) and \( Y \) are:

The statements that are TRUE:
(A) methane leads to both global warming and photochemical smog
(B) methane is generated from paddy fields
(C) methane is a stronger global warming gas than \( \mathrm{CO_2} \)
(D) methane is a part of reducing smog
Choose the most appropriate answer from the options given below:

Given below are two statements:
Statement I: Non-biodegradable wastes are generated by the thermal power plants
Statement II: Bio-degradable detergents leads to eutrophication.
In the light of the above statements, choose the most appropriate answer from the options given below:

Given below are two statements:
Statement I: Chlorofluoro carbons breakdown by radiation in the visible energy region and release chlorine gas in the atmosphere which then reacts with stratospheric ozone.
Statement II: Atmospheric ozone reacts with nitric oxide to give nitrogen and oxygen gases, which add to the atmosphere.
For the above statements choose the correct answer from the options given below:

Which of the following statements is NOT correct ?

Given below are two statements:
Statement : I The value of the parameter “Biochemical Oxygen Demand (BOD)” is important for survival of aquatic life.
Statement : II The optimum value of BOD is \( 6.5 \, \text{ppm} \)
In the light of the above statements, choose the most appropriate answer from the options given below

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JEE Main 2021 17th March Morning Shift

Reducing smog is a mixture of :