GATE Overflow for GATE ESE - Recent activity in Air Quality Management

Edited: GATE ES 2026 | Question: 50

Wed, 15 Apr 2026 12:04:22 +0000

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 $\mathrm{SO}_{2}$ concentrations through these sectors at this height are given in the table.

The mean $\mathrm{SO}_{2}$ concentration from the stack is $\_\_\_\_$ $\mathrm{mg} / \mathrm{m}^{3}$ (rounded off to two decimal places).

$$\begin{array}{|c|c|c|}
\hline
\begin{array}{c}
\textbf{Sector} \\
\textbf{Number}
\end{array}
&
\begin{array}{c}
\textbf{Velocity} \\
(\mathrm{m/s})
\end{array}
&
\begin{array}{c}
\mathrm{SO}_{2}\ \textbf{Concentration} \\
(\mathrm{mg}/\mathrm{m}^{3})
\end{array}
\\
\hline
1 & 15 & 1000 \\
\hline
2 & 17 & 1150 \\
\hline
3 & 19 & 1250 \\
\hline
4 & 21 & 1275 \\
\hline
\end{array}$$

Edited: GATE ES 2026 | Question: 30

Wed, 15 Apr 2026 10:37:56 +0000

Which ONE of the following options CORRECTLY matches the atmospheric stability conditions with plume conditions/ behaviours given in the table?

$$\begin{array}{|l|l|}
\hline
\begin{array}{c}
\textbf{Atmospheric Stability} \\
\textbf{Conditions}
\end{array}
&
\begin{array}{c}
\textbf{Plume Conditions/} \\
\textbf{Behaviours}
\end{array} \\
\hline
(P)\ \text{Strong instability} & (i)\ \text{Fanning plume} \\
\hline
(Q)\ \text{Neutral stability} & (ii)\ \text{Fumigation} \\
\hline
(R)\ \text{Surface inversion} & (iii)\ \text{Coning plume} \\
\hline
(S)\ \text{Aloft inversion} & (iv)\ \text{Looping plume} \\
\hline
\end{array}$$

$\text{(P) - (i); (Q) - (ii); (R) - (iii); (S) - (iv)}$
$\text{(P) - (iv); (Q) - (iii); (R) - (i); (S) - (ii)}$
$\text{(P) - (iii); (Q) - (iv); (R) - (ii); (S) - (i)}$
$\text{(P) - (ii); (Q) - (i); (R) - (iv); (S) - (iii)}$

Edited: GATE ES 2025 | Question: 17

Mon, 02 Jun 2025 16:53:27 +0000

Stubble burning results in release of particulate matter, volatile organic compounds, oxides of nitrogen and sulfur, to name a few. A researcher is planning to use a conventional Gaussian dispersion model to estimate the contribution of stubble burning in a nearby state to air pollution in New Delhi.

Choose the option(s) which could explain the possible limitations in this approach

assumption of steady state conditions e.g. constant wind speed, wind direction, and mission, etc. in conventional Gaussian dispersion models
non-accounting of wet and dry deposition in conventional Gaussian dispersion models
non-handling of chemical transformation of pollutants in conventional Gaussian dispersion models
requirement of more computational resources by conventional Gaussian dispersion models compared to chemical transport models

Recategorized: GATE ES 2023 | Question: 8

Mon, 21 Apr 2025 17:01:13 +0000

Which of the following is true according to the Central Pollution Control Board $\text{(CPCB)}$, Government of India's notification issued in the year $2009$?

$24$ hour averaged standard for $\mathrm{PM}_{2.5}$ in ambient air is $60 \mu \mathrm{g} / \mathrm{m}^3 ; 24$ hour averaged standard for $\mathrm{PM}_{10}$ in ambient air is $100 \mu \mathrm{g} / \mathrm{m}^3$
$24$ hour averaged standard for $\mathrm{PM}_{2.5}$ in indoor air is $60 \mu \mathrm{g} / \mathrm{m}^3 ; 24$ hour averaged standard for $\mathrm{PM}_{10}$ in ambient air is $100 \mu \mathrm{g} / \mathrm{m}^3$
$24$ hour averaged standard for $\mathrm{PM}_{2.5}$ in ambient air is $60 \mu \mathrm{g} / \mathrm{m}^3 ; 24$ hour averaged standard for $\mathrm{PM}_{10}$ in indoor air is $100 \mu \mathrm{g} / \mathrm{m}^3$
$24$ hour averaged standard for $\mathrm{PM}_{2.5}$ in indoor air is $60 \mu \mathrm{g} / \mathrm{m}^3 ; 24$ hour averaged standard for $\mathrm{PM}_{10}$ in indoor air is $100 \mu \mathrm{g} / \mathrm{m}^3$

Recategorized: GATE ES 2023 | Question: 9

Mon, 21 Apr 2025 17:01:10 +0000

The sub index values of $\mathrm{NO}_{2}, \mathrm{SO}_{2}$ and $\mathrm{PM}_{10}$ are $80,80$ and $100$, respectively. According to the National Air Quality Index $\text{(NAQI)}$ released by the Government of India in the year $2015$, the overall $\text{(NAQI)}$ is

$80$
$260$
$100$
$151$

Recategorized: GATE ES 2022 | Question: 13

Mon, 21 Apr 2025 16:47:23 +0000

Which one of the following is most commonly used raw material in flue gas desulfurization units?

Limestone
Titanium Oxide
Fenton reagent
Beryllium Oxide

Recategorized: GATE ES 2022 | Question: 37

Mon, 21 Apr 2025 16:46:16 +0000

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?

$\mathrm{SO}_{2}$ and $\mathrm{NO}_{2}$ have annual average standards; while $\mathrm{O}_{3}$ and $\mathrm{CO}$ have eight hour average standards.
$\mathrm{SO}_{2}$ and $\mathrm{CO}$ have annual average standards; while $\mathrm{O}_{3}$ and $\mathrm{NO}_{2}$ have eight hour average standards.
$\mathrm{SO}_{2}$ and $\mathrm{CO}$ have eight hour average standards; while $\mathrm{O}_{3}$ and $\mathrm{NO}_{2}$ have hourly average standards.
$\mathrm{SO}_{2}$ and $\mathrm{NO}_{2}$ have 24 hour average standards; while $\mathrm{O}_{3}$ and $\mathrm{CO}$ have hourly average standards.

Recategorized: GATE ES 2022 | Question: 38

Mon, 21 Apr 2025 16:46:13 +0000

Consider the figure shown below for three different cases:
Which of the following statement(s) is/are correct for surface level emissions, given the environmental temperature?

Case P represents unstable atmosphere and results in higher dispersion of emissions.
Case Q represents subsidence inversion and results in higher dispersion of emissions than Case P.
Case Q represents elevated inversion and results in lower dispersion of emissions than Case P.
Case R represents subsidence inversion and results in lower dispersion of emissions than Case P.

Recategorized: GATE ES 2021 | Question: 28

Mon, 21 Apr 2025 15:41:36 +0000

Match the entries in Column I with the correct entries in Column II.

Column I	Column II
Diffusion	Pasquill
Drag force	Fick
Atmospheric stability	Stokes

$\text{P-(iii), Q-(ii), R-(i)}$
$\text{P-(ii), Q-(i), R-(iii)}$
$\text{P-(i), Q-(iii), R-(ii)}$
$\text{P-(ii), Q-(iii), R-(i)}$