GATE Air and Noise Pollution: Air Quality Management – Previous Year Questions

16 GATE previous year questions on Air Quality Management (Air and Noise Pollution, Environmental Science and Engineering) with answers and explanations, from every paper.

GATE 2021 ES Q32 (1 mark, Multiple select) – Which quantities are represented in a wind rose?
GATE 2021 ES Q38 (2 marks, Multiple choice) – Match P diffusion, Q drag force, R atmospheric stability to i Pasquill, ii Fick, iii Stokes.
GATE 2022 ES Q30 (1 mark, Multiple select) – Which methods measure ambient PM₂.₅?
GATE 2022 ES Q47 (2 marks, Multiple select) – Under India’s2009 National Ambient Air Quality Standards, select correct averaging-time statements.
GATE 2022 ES Q64 (2 marks, Numerical answer) – A ground source emits1000 g/day SO₂. Temperature is 25°C at 10 m and 24.5°C at 110 m;wind2 m/s. At1 km,σy/σz (m) are50.5/21.4 stable,80/41.5…
GATE 2023 ES Q18 (1 mark, Multiple choice) – Under CPCB’s2009 notification, which24-hour standards are correct? All concentrations are µg/m³.
GATE 2023 ES Q19 (1 mark, Multiple choice) – Under India’s2015 National AQI, NO₂,SO₂,PM₁₀ subindices are80,80,100. Find overall AQI.
GATE 2023 ES Q61 (2 marks, Numerical answer) – An80 m effective stack emits1200 g/hour CO. The windrose is shown. Dispersion coefficients (σy, σz), in m: Northeast (50, 20); North (45, 30);…
GATE 2024 ES Q59 (2 marks, Numerical answer) – A stack emits100 g/s CO at effective height H. Wind speed is 5 m/s. At3 km downwind,σy=50 m andσz=25 m. Find plume-centerline concentration in…
GATE 2025 ES Q20 (1 mark, Multiple choice) – P:Under India’s 2009 NAAQS, the annual time-weighted PM 10 standard exceeds the PM 2.5 standard. Q:Under the National AQI released in 2015,the PM 10…
GATE 2025 ES Q27 (1 mark, Multiple select) – A researcher uses a conventional Gaussian plume model to estimate New Delhi pollution caused by nearby-state stubble burning, which emits particles,…
GATE 2025 ES Q42 (2 marks, Multiple choice) – Which gives the best dioxin/furan control for waste-incinerator flue gas?
GATE 2026 ES Q39 (2 marks, Multiple choice) – Match CPCB continuous ambient monitoring pollutants P SO 2 (µg/m³),Q NO 2 (µg/m³),R PM 2.5 (µg/m³),S CO (mg/m³) with methods (i)…
GATE 2026 ES Q40 (2 marks, Multiple choice) – Match stability P Strong instability, Q Neutral stability, R Surface inversion, S Aloft inversion with plume behavior (i) Fanning,(ii)…
GATE 2026 ES Q46 (2 marks, Multiple select) – Which are assumptions of the Gaussian plume dispersion model? Select all that apply.
GATE 2026 ES Q60 (2 marks, Numerical answer) – At height 30 m, a stack cross-section is divided into four equal sectors. Sector velocities are 15,17,19,21 m/s and corresponding SO 2 concentrations…