Revised National Ambient Air Quality Standards (NAAQS) 18th November, 2009
Practice Previous Exam Questions:
1. PM2.5 concentrations in ambient air can be measured using (GATE 2022)
(A) Beta attenuation method
(B) Chemiluminescence method
(C) Gravimetric method
(D) Non dispersive infrared spectroscopy method
Answer: (A) Beta attenuation method and (C) Gravimetric method
2. The 24 Hour National Ambient Air Quality Standard for PM2.5 in India is
(A) 20
(B) 50
(C) 60
(D) 75
Answer: (C) 60