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Railways PYQCBT 1 2016

RRB NTPC · Question 56

National Air Quality Index is determined on the basis of concentration of ________ pollutants.

  1. 5
  2. 6
  3. 7
  4. 8
Show answer & explanation

Answer: (D) 8

Explanation

India's National Air Quality Index (2014) uses eight pollutants: PM10, PM2.5, NO₂, SO₂, CO, O₃, NH₃ and Pb.