Engineering Questions with Answers - Multiple Choice Questions

Environmental Science MCQ – Air Pollution – Analysis

1 - Question

What is the principle behind which opacity monitors/transmissometers work?
a) Change in capacitance for various gaseous media, between two stationary plates
b) Pressure exerted by a fixed volume of gas enclosed in a container of specific dimension
c) Scattering of light transmitted through a gas stream
d) None of the mentioned

View Answer

Answer: c
Explanation: Like the name suggests, opacity monitors or transmissometers work by transmitting light into a particular stream of gas, and gives information regarding the combustion conditions and efficiency.




2 - Question

Are any of the following monitors used to measure the concentration of particular gases from the exhaust generated in vehicles?
a) Opacity monitors
b) Gaseous emission monitors
c) Opacity & Gaseous emission monitors
d) None of the mentioned

View Answer

Answer: b
Explanation: These monitors are used to measure the concentrations of certain gases such as oxygen, carbon monoxide, oxides of sulphur and nitrogen from the exhaust.




3 - Question

What does the abbreviation NDIR stand for, in the category of spectrometric analysers?
a) Non-Destructive Integrated Restoration
b) Neo-Destructive Integrated Radiation
c) Non-Dispersive Infrared
d) Neo-Dispersive Integrated Radiation

View Answer

Answer: c
Explanation: NDIR detectors/analysers are used to monitor sulphur dioxide, oxides of nitrogen and carbon, hydrocarbons, etc.




4 - Question

Non-Dispersive Ultraviolet (NDUV) analysers are primarily used to detect which of the following two gases?
a) Oxygen and Carbon Dioxide
b) Oxygen and Nitrogen Dioxide
c) Nitrogen Dioxide and Sulphur Dioxide
d) Sulphur Dioxide and Oxygen

View Answer

Answer: c
Explanation: NDUV analysers are mainly used to detect nitrogen dioxide and sulphur dioxide.




5 - Question

NDUV monitors use a reference gas to analyse other gases.
a) True
b) False

View Answer

Answer: b
Explanation: NDIR monitors use a reference gas for analysis and not NDUV, which is the main difference between the two.




6 - Question

NDUV analysis is also known as the differential absorption.
a) True
b) False

View Answer

Answer: a
Explanation: NDUV method uses a reference wavelength which has less absorption capabilities to find out variations in absorption with respect to this reference wavelength in different media.




7 - Question

Fluorescence analysers are used to analyse which of the following gases?
a) Nitrogen dioxide
b) Sulphur dioxide
c) Sulphur trioxide
d) Nitrous oxide

View Answer

Answer: b
Explanation: Fluorescence occurs when a molecule is excited by light energy of specific wavelength and emits light energy of another wavelength.




8 - Question

Electroanalytical monitors rely on which of the following methods?
a) Polarography and amperometric analysis
b) Polarography and electrocatalysis
c) Polarography, electrocatalysis and conductivity
d) All of the mentioned

View Answer

Answer: d
Explanation: Electroanalytical instruments rely on polarography, conductivity, electrocatalysis and amperometric analysis.




9 - Question

Which of the following analyser is used for oxygen analysis?
a) Electrocatalytic
b) Polarographic
c) Conductive
d) Amperometric

View Answer

Answer: a
Explanation: Electrocatalytic analysers are used for oxygen monitoring.




10 - Question

In-situ cross stack analysers work behind which of the following principles?
a) Differential absorption spectroscopy
b) Gas-filter correlation spectroscopy
c) Differential absorption & Gas-filter correlation spectroscopy
d) None of the mentioned

View Answer

Answer: c
Explanation: Cross stack analysers work behind the principles of differential absorption/gas-filter correlation spectroscopy.




11 - Question

In-situ in-stack analysers are used for measuring concentrations of which of the following gases?
a) Ammonia
b) Sulphur dioxide
c) Nitrogen monoxide
d) All of the mentioned

View Answer

Answer: d
Explanation: In-site in-stack analysers work on the principle of second derivative spectroscopy to measure concentrations of ammonia, sulphur dioxide and nitrogen monoxide.




12 - Question

What is the disadvantage of using conductometric analysers?
a) Low sensitivity
b) Interfering gases must be removed before monitoring process
c) Medium used to measure change in conductivity is expensive
d) All of the mentioned

View Answer

Answer: b
Explanation: Conductometric analysis is a non-specific method and hence requires interfering gases to be removed before monitoring process.




13 - Question

Flame photometric analysers are specific to sulphur compounds.
a) True
b) False

View Answer

Answer: a
Explanation: Flame photometric analysers work behind the principle of luminescence through molecule/flame interaction and their use is limited to detect sulphur compounds alone.




14 - Question

Airshed modelling takes into account the effects of only stationary sources and not the mobile sources of pollution.
a) True
b) False

View Answer

Answer: b
Explanation: Airshed modelling takes into account the effects of both mobile and stationary sources scattered in a small geographical region.

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