List of top Air and Noise Pollution Questions asked in GATE ES

A boiler burns coal at a rate of 1 kg/s. If the coal has 3% sulfur content, assuming that there is no sulfur in ash, SO2 emitted is ________ kg/day. (rounded off to nearest integer)
Which option gives the best control strategies for Dioxins and Furans in the flue gas emitted from waste incineration facilities?
At a pressure of 1 atmosphere and temperature of 25\(^{\circ}\)C, 365 µg m\(^{-3}\) of a pollutant corresponds to a mixing ratio of 139 parts per billion (ppb). The atomic weights: C – 12, H – 1, O – 16, N – 14 and S – 32. Which one of the following options most closely represents the pollutant?
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.
The equipment that can be used to control particulate air pollution in an industrial unit is/are
Which is/are the secondary air pollutant(s)?
A gravity settling chamber of height ‘H' and length ‘L' is designed to control particulate air pollution. In the chamber, the horizontal velocity of air flow is $'V_h'$ and terminal settling velocity of the target particle is $'V_ť$. Which one of the following expressions is the correct concept used to calculate the minimum size of the target particle that will be removed with 100% efficiency?
In a cyclone separator of radius 25 cm, a particle is travelling with a gas stream at velocity of 18 m/s. The ratio of centrifugal force to the gravitational force acting on the particle is ________(rounded off to 2 decimal places).
Consider acceleration due to gravity (g) as 9.8 m/s2.
Two sources of noise, adjacent to each other in a room, have sound pressure levels of 30 and 40 decibel (dB). The combined sound pressure level in the room is _________ dB(rounded off to 2 decimal places).
Use reference sound pressure as $20 \mu Pa$.
An industrial stack emits 100 g/s of CO at an effective height of 'H', where the wind speed is 5 m/s. At 3 km distance downwind, the values of dispersion coefficient in y- direction and z-direction are 50 m and 25 m, respectively. The CO concentration at the centerline of the plume at 3 km distance downwind is ________ \(mg/m^3\) (rounded off to 2 decimal places)?  Use Gaussian plume model and value of \(\pi\) = 3.14. Neglect reactions and the ground effect of plume in the calculations.

Match the following: Plastic Types and Applications 

CodePlastic TypeCommon Applications
PHigh-density polyethylene (HDPE)(iv) Geomembrane for landfill liner
QLow-density polyethylene (LDPE)(i) Garbage bags, bubble packaging
RPolyethylene terephthalate (PET)(iii) Water bottles
SPolystyrene (PS)(ii) Pharmaceutical bottles, Styrofoam cups
Place the following international conventions/conferences/protocols/declarations in the chronological order (oldest to latest) of their happening:
(i) United Nations conference in Stockholm which resulted in the establishment of the United Nations Environmental Program (UNEP)
(ii) Vienna convention for the protection of the Ozone layer
(iii) United Nations climate change conference in Glasgow commonly referred as COP26
(iv) Montreal protocol on phasing out production of substances related to Ozone layer depletion
Which of the following is true according to the Central Pollution Control Board (CPCB), Government of India’s notification issued in the year 2009?
The sub index values of NO$_2$, SO$_2$ and PM$_{10}$ 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:
A ground level source emits 1000 g/day of SO$_2$. Wind speed = 2 m/s. Dispersion coefficients at 1000 m downwind are given. Estimate the ground-level SO$_2$ concentration (in $\mu$g/m$^3$, rounded off to two decimals) at 1000 m at the plume centerline.
According to the National Ambient Air Quality Standards (CPCB, Govt. of India, 2009), which of the following statement(s) is/are correct?
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?
During night, in troposphere, which of the following is/are NOT correct?
A relatively calm room has background sound power level (SPL) of 30 decibels (dB). A television and a radio with SPL of 80 dB and 70 dB, respectively, started operating simultaneously in this room. Given the reference sound power is $10^{-12}$ Watts, what will be the resulting SPL in the room, assuming all the sources operate independently?
A bag filter is used for removal of particulate matter having a range of sizes. The correct sequence of air filtration mechanisms for their removal, in order of decreasing size, is
PM$_{2.5}$ concentrations in ambient air can be measured using
Which one of the following is most commonly used raw material in flue gas desulfurization units?
In the context of noise pollution, SPL is the sound pressure level in decibels (dB). The relationship between SPL, the root mean square (rms) sound pressure \( p \), and the reference (hearing threshold) pressure \( p_0 \) is expressed as _______.
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 ppmv (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 _______.
The concentration of NO\(_2\) in the air at NTP is reported as 0.30 ppm (ppm by volume). The concentration of NO\(_2\) in \(\mu g/m^3\) is _______ (rounded off to the nearest integer).