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Class 8 · Science & Environment

Ch 8 · Nature of Matter: Elements, Compounds, and Mixtures

Real UPSC Prelims questions from 2016–2026, linked to this book. Try each one first, then open the answer. 2026 answers follow UPSC's provisional answer key.

Prelims 2016 · Q86

In the cities of our country, which among the following atmospheric gases are normally considered in calculating the value of Air Quality Index?

  1. 1.Carbon dioxide
  2. 2.Carbon monoxide
  3. 3.Nitrogen dioxide
  4. 4.Sulfur dioxide
  5. 5.Methane

Select the correct answer using the code given below.

  1. (a)1, 2 and 3 only
  2. (b)2, 3 and 4 only
  3. (c)1, 4 and 5 only
  4. (d)1, 2, 3, 4 and 5
Show answer

UPSC's answer: (b)

NCERT answers it: Class 8 Curiosity, Ch 8 (Nature of Matter: Elements, Compounds, and Mixtures).

How to solve it with NCERT: Class 8 Curiosity, ch 8: the major air pollutants are particulate matter, carbon monoxide, ozone, nitrogen dioxide and sulfur dioxide, and the Air Quality Index describes air quality. Carbon dioxide and methane are not on that list. Answer (b).

Beyond NCERT: India's National Air Quality Index (CPCB) uses eight pollutants: PM10, PM2.5, nitrogen dioxide, sulphur dioxide, carbon monoxide, ozone, ammonia and lead. Carbon dioxide and methane are not among them. Source: CPCB, 'About National Air Quality Index' (cpcb.nic.in)

Hindi version: UPSC's official question paper (2016), question 86 ↗

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