EMISSIONS INSPECTOR
CERTIFICATION EXAM WITH CORRECT
ANSWERS 2025
air pollution ( Correct answers ) the contamination of the
atmosphere of
introduction by pollutants
the from human and natural
sources
United States Environmental Protection Agency (EPA) ( Correct answers )
Estimated
that 20% of all US pollution comes from cars
and trucks
Major pollutants from vehicles ( Correct answers ) Hydrocarbons
(HCs), Carbon
Monoxide (CO), Nitrogen Oxides (NOx). Other pollutants includes Sulfur
Dioxide
and (SO2)
Particulate
Matter.
Hydrocarbons ( Correct answers ) Principal constituents of gasoline,
diesal, and
natural gas. Excessive amounts of this pollutant is mainly from incomplete
combustion
and rich fuel mixtures. Tends to stay consistent with the
stoichiometric ratio.
Nitrogen Oxides ( Correct answers ) Forms with HC to create smog; mainly
formed engines
vehicle in during combustion of fuel at high temperatures. Primary
cause of acid
rai
n
Oxygen ( Correct answers ) Too much or too little is bad and can
cause improper
combustion. Too little can be from rich air-fuel mixture, and dirty air
filters.
can be Too
caused
muchby lean air-fuel mixture or engine
misfires.
Ozone(Smog) ( Correct answers ) Not emitted directly into the air, but
created level
ground at by chemical reactions from NOx and HC. Also known
as smog.
Particulates ( Correct answers ) This matter is released into the air by
and can damage the lungs and cause health
combustion
problems
Five Gas Theory ( Correct answers ) Shows how the ratio of each gas to
the others
changes in response to different temperatures and fuel
mixtures
Lean Mixture ( Correct answers ) Low ratio of
fuel to air
CERTIFICATION EXAM WITH CORRECT
ANSWERS 2025
air pollution ( Correct answers ) the contamination of the
atmosphere of
introduction by pollutants
the from human and natural
sources
United States Environmental Protection Agency (EPA) ( Correct answers )
Estimated
that 20% of all US pollution comes from cars
and trucks
Major pollutants from vehicles ( Correct answers ) Hydrocarbons
(HCs), Carbon
Monoxide (CO), Nitrogen Oxides (NOx). Other pollutants includes Sulfur
Dioxide
and (SO2)
Particulate
Matter.
Hydrocarbons ( Correct answers ) Principal constituents of gasoline,
diesal, and
natural gas. Excessive amounts of this pollutant is mainly from incomplete
combustion
and rich fuel mixtures. Tends to stay consistent with the
stoichiometric ratio.
Nitrogen Oxides ( Correct answers ) Forms with HC to create smog; mainly
formed engines
vehicle in during combustion of fuel at high temperatures. Primary
cause of acid
rai
n
Oxygen ( Correct answers ) Too much or too little is bad and can
cause improper
combustion. Too little can be from rich air-fuel mixture, and dirty air
filters.
can be Too
caused
muchby lean air-fuel mixture or engine
misfires.
Ozone(Smog) ( Correct answers ) Not emitted directly into the air, but
created level
ground at by chemical reactions from NOx and HC. Also known
as smog.
Particulates ( Correct answers ) This matter is released into the air by
and can damage the lungs and cause health
combustion
problems
Five Gas Theory ( Correct answers ) Shows how the ratio of each gas to
the others
changes in response to different temperatures and fuel
mixtures
Lean Mixture ( Correct answers ) Low ratio of
fuel to air
