GATE ES Air pollution PYQs & Answers

Questions 1–10 of 12. Imported answers require independent review unless marked reviewed.

Which ONE of the following options CORRECTLY matches the Criteria Air Pollutants with measurement methods used in Continuous Ambient Air Quality Monitoring Stations (CAAQMS) operated by Central Pollution Control Board (CPCB) given in the table?

Criteria Air Pollutants	Measurement Methods
(P) Sulphur Dioxide (SO , in μg/m )	(i) Chemiluminescence
(Q) Nitrogen Dioxide (NO , in μg/m )	(ii) Non Disperse Infra Red (NDIR) spectroscopy
(R) Particulate Matter (PM , in μg/m )	(iii) Ultraviolet fluorescence
(S) Carbon Monoxide (CO, in mg/m )	(iv) Beta attenuation

Your answerChoose one option.

(P) - (i); (Q) - (ii); (R) - (iii); (S) - (iv)

(P) - (iv); (Q) - (iii); (R) - (ii); (S) - (i)

(P) - (iii); (Q) - (i); (R) - (iv); (S) - (ii)

(P) - (ii); (Q) - (iii); (R) - (i); (S) - (iv)

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The mixing ratio of CO₂ at a pressure of 1 atm and at 300K is reported as 340 ppmv. Considering ideal gas conditions, the equivalent concentration of CO₂ in air is ______ mg/m³ (rounded off to two decimal places).

The molecular weight of CO₂ = 44 g/mol

Universal gas constant = 8.314 J/mol-K

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In a stack emission measurement at an industry, the stack cross-sectional area at 30 m height was divided into four equal sectors. The measured velocities and SO

concentrations through these sectors at this height are given in the table.

The mean SO

concentration from the stack is _____ mg/m

(rounded off to two decimal places).

Sector Number	Velocity (m/s)	SO Concentration (mg/m )
1	15	1000
2	17	1150
3	19	1250
4	21	1275

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The concentration of chemical A in ambient air is 50 μg/m

and the toxicological index limit for a threshold health effect for this chemical is 5 mg.

If the average breathing rate is 4 L/min, the minimum time of exposure that can lead to any health effect is _____ days (rounded off to one decimal place).

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Which is/are the secondary air pollutant(s)?

Your answerSelect all correct options. You can choose more than one.

O₃

HNO₃

CO₂

H₂SO₄

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Which of the following is true according to the Central Pollution Control Board (CPCB), Government of India’s notification issued in the year 2009?

Your answerChoose one option.

24 hour averaged standard for PM₂.₅ in ambient air is 60 μg/m³; 24 hour averaged standard for PM₁₀ in ambient air is 100 μg/m³

24 hour averaged standard for PM₂.₅ in indoor air is 60 μg/m³; 24 hour averaged standard for PM₁₀ in ambient air is 100 μg/m³

24 hour averaged standard for PM₂.₅ in ambient air is 60 μg/m³; 24 hour averaged standard for PM₁₀ in indoor air is 100 μg/m³

24 hour averaged standard for PM₂.₅ in indoor air is 60 μg/m³; 24 hour averaged standard for PM₁₀ in indoor air is 100 μg/m³

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The sub index values of NO₂, SO₂ and PM₁₀ are 80, 80 and 100, respectively. According to the National Air Quality Index (NAQI) released by the Government of India in the year 2015, the overall NAQI is

Your answerChoose one option.

260

100

151

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In a 30 m³ room, a stove in operation consumes wood at the rate of 0.25 kg/h. The inflow and outflow rate of air in the room is the same, i.e. 500 m³/h. This stove emits a VOC species at a rate of 0.2 g/kg-wood. The VOC species gets converted to CO₂ at a rate of 0.4 per hour. Given: (i) the air in the room is completely mixed, (ii) initial concentration of the VOC species in the room is negligible, and (iii) concentration of the VOC species in the air entering the room is negligible. The concentration of the VOC species due to two hours of stove operation in the room is __________(in μg/m³, rounded off to one decimal place).

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According to the National Ambient Air Quality Standards (Central Pollution Control Board, Govt. of India, notification 2009) which of the following statement(s) is/are correct?

Your answerSelect all correct options. You can choose more than one.

SO₂ and NO₂ have annual average standards; while O₃ and CO have eight hour average standards.

SO₂ and CO have annual average standards; while O₃ and NO₂ have eight hour average standards.

SO₂ and CO have eight hour average standards; while O₃ and NO₂ have hourly average standards.

SO₂ and NO₂ have 24 hour average standards; while O₃ and CO have hourly average standards.

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A sample of air is collected in the morning at an ambient temperature of 25 °C. The concentration of carbon monoxide (CO) in this sample is 30 ppm (ppm by volume). The same sample is analysed later in the afternoon when the sample temperature is 35 °C. The analysis results will show the CO concentration as __________.

Your answerChoose one option.

< 29 ppm

30 ppm

= 30 ppm

= 29 ppm

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GATE ES Air pollution PYQs

How to practice Air pollution

Question 39

Question 49

Question 60

Question 63

Question 30

Question 18

Question 19

Question 59

Question 47

Question 4