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AP TET Paper 1 Model Test 2

Question : 141 of 150

Marks: +1, -0

Which of the following is a secondary pollutant?

$O_{3}$
SO2
$CO_{2}$
CO

Solution:

Concept:

Pollutants can be classified by their origin. Primary pollutants are released directly from sources, whereas secondary pollutants form in the atmosphere through chemical or photochemical reactions.

Explanation:

Primary pollutants are emitted straight into the air from natural or human activities, such as carbon monoxide (CO), sulfur dioxide (SO2), and carbon dioxide (CO2). Secondary pollutants are not emitted directly; they result from reactions of primary pollutants in the presence of sunlight or other conditions. Ozone (O3) is a classic example — it forms when nitrogen oxides and volatile organic compounds react. Among the given options, SO2, CO2, and CO are primary pollutants. Only O3 is a secondary pollutant.

The table below lists common examples:

Primary Pollutants

Secondary Pollutants

Carbon monoxide (CO)

Oxides of nitrogen (NOx, NO)

Sulfur oxides (SOx)

Volatile organic compounds (VOCs) highly

Particulate matter (dust, ash, salt particles)</td> < td>Ozone

PAN

Smog

Formaldehyde

Sulphuric Acid</td></tr></table></div> < br> < b>Answer:</b> < br> A.

O_{3}$

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