Engineering Chemistry MCQ’S Unit-4

FUELS:
INTRODUCTION – CLASSIFICATION OF FUELS

1.Which type of fuel is lignite?
a) Secondary fuel
b) Primary fuel

c) Liquid fuel
d) Gaseous fuel
Answer: b
Explanation: Lignite is a primary fuel as it
can be extracted from nature without any sort
of transformation process. Lignite is soft
brown coal. It is considered as the lowest
rank of coal.

2.Acetylene and synthesis gas are examples of
a) Primary gaseous fuels
b) Gaseous fuels
c) Secondary gaseous fuels
d) Liquid fuels
Answer: c
Explanation: Since both Acetylene and
synthesis gas are formed by certain process
and both are gaseous in nature, therefore they
are secondary gaseous fuels. Acetylene can
be formed by the hydrolysis of calcium
carbide.
3.Alcohol is a primary fuel.
a) True
b) False
Answer: b
Explanation: Alcohol are formed by direct
hydration of alkenes, that is why this is a false
statement. Formation of ethanol by the
hydration of ethylene.
C₂H₄ + H₂O → C₂H₅OH
4.Which of the fuel does have highest
specific energy?
a) Diesel
b) Coal
c) Kerosene
d) Nitromethane
Answer: a
Explanation: Specific energy is the amount
of energy liberated after combustion, as
among these diesel liberated the highest
amount of energy which is 48 MJ/kg.
5.Which type of coal give more amount of
heat after combustion?
a) Anthracite
b) Peat
c) Lignite
d) Bituminous
Answer: a
Explanation: The coal is formed along this process
Peat → Lignite → Bituminous → Anthracite
Since anthracite is the purest form of the coal,
it gives the highest amount of heat after combustion.
6.Which fuel is best suitable for blast furnace
process?
a) Diesel
b) Hydrogen Gas
c) Coal
d) Coke
Answer: d
Explanation: Coke is best suitable for blast
furnace process as it also acts as a reducing
agent in smelting iron ore. The specific heat
of coke is 0.85 kJ/kg K.
7.Which fuel causes least pollution?
a) Diesel
b) Coal
c) LPG (Liquid Petroleum Gas)
d) Hydrogen gas
Answer: d
Explanation: Pollution is mainly caused by
the presence of CO₂ in air. Since after
combustion of H₂ it only gives water vapour
which is less polluting.
8.Which of the gas is not a constituent of
biogas?
a) Methane
b) Hydrogen
c) CO₂
d) SO₂(Sulphur di-oxide)

Answer: d
Explanation: Since biogas is formed by the
domestic waste of home and industries, it
does not contain the gases like SO₂, NO₂etc.
It does contain the hydrogen sulphide.

9.Which fuel can be produced from the
carbohydrate content of algae?
a) Butanol
b) Hydrogen gas
c) Coal
d) LPG (Liquid Petroleum Gas)
Answer: a
Explanation: The carbohydrate part of algae
is fermented due to which Butanol is
produced. By this process, bio-ethanol can
also be produced.
10.Which of the following fuel cannot be
used in producing nuclear energy?
a) Plutonium
b) Uranium
c) Tritium
d) Deuterium
Answer: d
Explanation: Since deuterium contains two
electrons in its shell, it becomes difficult to
break into a fully filled octet, due to which it
cannot be used as a fuel in nuclear energy.

COAL

1.How does the texture of coal changes with
its maturity?
a) Becomes hard, less brittle and moderately
tough
b) Becomes hard, more brittle and more tough
c) Becomes hard, more brittle and less tough
d) No change
Answer: b
Explanation: The texture of coal tends to the
layer present on the coal and its maturity is
from lignite to anthracite. The number of
layers from lignite to anthracite increases due
to which the compactness increase, thus
increasing its toughness, hardness and
brittleness.
2.On what factors does the specific gravity of
coal depends?
a) Its calorific value and ash content
b) Its ignition temperature and calorific value
c) Type of coal and ash content
d) Type of coal and calorific value
Answer: c
Explanation: Specific gravity is the ratio of
the density/mass of a substance to the
density/mass of reference substance. The total
ash content represents its mass and
The type of coal is required for its density.
3.Which of the coal have the best heating
values in terms of volatile matter?
a) Containing 20% volatile matter
b) Containing 60% volatile matter
c) Containing 30% volatile matter
d) Containing 50% volatile matter
Answer: a
Explanation: Coals containing high volatile
matter produces long and smoky flame due to
which its heating value decreases. Semibituminous coal has the highest heating value
due to less volatiles content.
4.Which type of coals have the highest
grindability index?
a) Steam coals
b) Gas coals
c) House coals
d) Pulverised coals
Answer: d
Explanation: Grindability is the ease with which a coal can be grounded. The grindability index of pulverised coal is about This is because of the volatile matter present in the coal, the higher the volatile matter of coal, the more will be its grindability index.

5.How does the friability of the coal is
tested?
a) Drop shatter test
b) Thermal cracking
c) Knocking
d) Proximate analysis
Answer: a
Explanation: Friability is the tendency of the
coal to break into pieces. The more the
friability, the less will be the quality of coal.
Splint and cannel coal are less friable.
Knocking is the unusual sound produced by
an engine.
6.Which property of coal is tested in
Audibert Arnu test?
a) Bulk density
b) Colour
c) Caking and coking
d) Texture
Answer: c
Explanation: This method uses a dilatometer
to find out the swelling properties of coal.
Caking is the ability to form a coherent cake
when the coal is carbonised. If there is
residue formed during carbonisation, then the
coals formed are called coking coals.
7.On which property of coal does the design
of bunkers for the storage of coal depends?
a) Specific gravity
b) Bulk density
c) Grindability
d) Friability
Answer: b
Explanation: Bunkers/coal bins are the containers in which the coal can be transported. Bulk density is weight of soil present in coal. According to the bulk density the design of containers are generated.

8.Which type of coals are non-caking in
nature?
a) Steam coals
b) Gas coals

c) House coals
d) Pulverised coals
Answer: a
Explanation: Steam coals are volatile
lignitous coals which are used in steam
raising. These coals produce long smoky
flames. Gas coals are strongly caking in
nature.

9.Phosphorous and sulphur content in the
coal tend to make a metal brittle.
a) True
b) False
Answer: a
Explanation: A coal should not contain high
phosphorous and sulphur content because
coal have a role in number of metallurgical
operation due to which it affects the
properties of metal and makes it brittle.
10.Which of the following is not a
characteristic of coal?
a) Weathering
b) Slaking index
c) Moisture content
d) Bulk density
Answer: c
Explanation: Moisture content represents the
total vapours present inside the coal. Moisture
develops from the outside atmospheric
conditions due to which it is not a
characteristic of coal

ANALYSIS OF COAL (PROXIMATE AND ULTIMATE). CARBONIZATION

1.In analysis of coal, determination of is done by Kjeldahl method.

a) Volatile matter
b) Nitrogen
c) Ash
d) Oxygen

Answer: b
Explanation: In ultimate analysis of coal,
Nitrogen is determined by Kjeldahl method.
The method involves 3 steps which are
digestion, distillation and titration. In
digestion, sample is digested in boiling
concentrated sulphuric acid in presence of
catalyst and ammonium sulphate is obtained.
In distillation, excess NaOH solution is added
and ammonia is obtained. In titration,
ammonia is determined by volumetric acid
solution. The result can be expressed in terms
of %N.

2.In determination of carbon and hydrogen
by ultimate analysis, increase in weight of
calcium chloride bulb represents
a) weight of water formed
b) weight of carbon dioxide formed
c) carbon
d) hydrogen
Answer: a
Explanation: The gaseous products of
combustion are passed through two bulbs.
One containing weighed amount of
anhydrous Calcium chloride which absorbs
water other containing weighed amount of
potassium hydroxide which absorbs carbon
dioxide.
3.Hydrogen available for combustion is
lesser than the actual one.
a) true
b) false
Answer: a
Explanation: Oxygen is present in combined
form with hydrgen in the coal. It is very
difficult to break hydrogen-oxygen bond and
hence, that combined form of hydrogen is not
available for combustion. Thus, free
hydrogen available for combustion is lesser
than the actual one.
4.Good quality of coal should have %
of oxygen.
a) low
b) high
c) 100
d) 0
Answer: a
Explanation: Good quality of coal should
have less % of oxygen because increase in
1% oxygen content decreases calorific value
approximately by 1.7%. Ideal fuel should
have high calorific value and hence, less
%oxygen.
5.Percentage of ash by analysis of coal is
given by
a) (weight of residue/weight of sample) × 100
b) (weight of sample – weight of residue) ×
100
c) (weight of sample – weight of
residue)/weight of sample × 100
d) (weight of residue – weight of sample) ×
100
Answer: a
Explanation: Ash is weight of residue
obtained after complete combustion of 1 g of
coal at 700‐ 750°C. Ash in % is given by,
%A= (weight of residue/weight of sample) × 100.
6.In coal, Sulphur is usually present in the
extent of
a) 0.5-3%
b) 90-95%
c) 70-75%
d) 80-85%
Answer: a
Explanation: Sulphur is generally present in
the extent of 0.5 to 3% and is usually derived
from ores like gypsum, iron pyrites, etc. High
percentage of sulphur in coal is undesirable to
be used for making coke in the iron industry
since it affects the quality and properties of
steel.
7.In ultimate analysis, %hydrogen is given by
a) (Increase in weight of CaCl₂ tube×2×100 / weight of coal sample taken×18)

b) (Increase in weight of KOH tube×2×100 /
weight of coal sample taken×18)
c) (Increase in weight of CaCl₂tube×4×100 /
weight of coal sample taken×18)
d) (Increase in weight of KOH tube×4×100 /
weight of coal sample taken×18)
Answer: a
Explanation: %hydrogen= (weight of
hydrogen/weight of coal sample taken) × 100
In ultimate analysis of coal,
%H = (Increase in weight of CaCl₂
tube×2×100 / weight of coal sample
taken×18)

7.In ultimate analysis, %carbon is given by
a) (Increase in weight of KOH tube×12×100 /
weight of coal sample taken×44)
b) (Increase in weight of KOH tube×2×100 /
weight of coal sample taken×18)
c) (Increase in weight of CaCl₂ tube×12×100/ weight of coal sample taken×44)
d) (Increase in weight of CaCl₂ tube×2×100 /
weight of coal sample taken×18)
Answer: a
Explanation: %C = (weight of carbon/weight
of coal sample taken) ×100
In the ultimate analysis of coal,
%C = (Increase in weight of KOH
tube×12×100 / weight of coal sample
taken×44).
9.is the weight of residue
obtained after burning a weighed amount of
dry coal.
a) Ash
b) Volatile matter
c) Moisture
d) Carbon
Answer: a
Explanation: Ash is an unwanted matter and
non-combustible which is the residue left
after all combustible substances are burnt off.
%Ash= (weight of ash formed/weight of dry
coal taken) × 100.
10.In proximate analysis of coal, %fixed
carbon =
a) 100 – % (ash + volatile matter + moisture)
b) 100 – % (ash + moisture)
c) 100 – % (ash + moisture) + %volatile matter
d) 100 – % (moisture + volatile matter)
Answer: a
Explanation: In proximate analysis of coal,
firstly percentage of ash, volatile matter and
moisture is found out. Percentage of fixed
carbon can be found out by subtracting the
above percentages from 100 since coal
consists of ash, moisture, volatile matter and
fixed carbon.

PETROLEUM

1.What is the primary component of crude
oil?
a) Sulfur
b) Carbon
c) Hydrogen
d) Nitrogen
Answer: b
Explanation: Crude oil is greenish brown and
viscous oil found on the earth’s surface. It is
primarily composed of hydrocarbons (79.5-
87.1%) followed by hydrogen (11.5-14.8%),
sulfur (0.1-3.5%), and nitrogen and oxygen
(0.1-0.5%).
2.How is crude oil separated?
a) Crystallization
b) Fractional distillation
c) Decantation
d) Sublimation
Answer: b
Explanation: Crude oil is usually suspended on a layer of brine with a deposit of gas over it. This form is usually not preferred for any useful applications. The crude oil is therefore separated by fractional distillation and converted into desired products.

3.What type of gas is LPG?
a) Gasoline
b) Kerosene
c) Uncondensed
d) Heavy oil
Answer: c
Explanation: Crude oil separated by
fractional distillation is made into a number
of products such as uncondensed gas. This
gas is used for domestic and industrial
applications by the name liquefied petroleum
gas (LPG).
4.What is the boiling temperature of petrol?
a) 40-120oC
b) 120-180oC
c) 180-250oC
d) 250-320oC
Answer: b
Explanation: Petrol, otherwise known as
gasoline, is commonly used as motor fuel. It
may also be used as a solvent and in dry
cleaning applications. Petrol has a boiling
temperature range of 120-180oC.
5.Which fuel/oil is used for obtaining
gasoline?
a) Kerosene
b) Diesel
c) Heavy
d) Naphtha
Answer: c
Explanation: Heavy oil is a crude oil product
used for acquiring gasoline by cracking
process. It has a boiling temperature range of
250-320oC. This gasoline, in turn, is used for
motor fuel.
6.Which of the following is not used as a
lubricant?
a) Lubricating oil
b) Grease
c) Asphalt
d) Petroleum jelly
Answer: c
Explanation: Lubricating oils and grease are
primarily used as lubricating agents, while
petroleum jelly is used for lubrication as well
as in cosmetics and medicines. Asphalt is a
residue type product used for waterproofing
of roofs and to make roads.
7.What is the function of petroleum coke?
a) Lubrication
b) In candles
c) As fuel
d) As solvent
Answer: c
Explanation: Petroleum coke is a carbon-rich
group of products used as fuel. Petcoke is one
such type of the product, which is derived
from cracking process. Raw coke is referred
to as green coke.
8.Carbon black and hydrogen can be
manufactured using
a) Natural gas
b) Coal gas
c) Oil gas
d) Water gas
Answer: a
Explanation: Natural gas is obtained from
wells in oil-rich regions. It acts as a domestic
fuel and is also used to manufacture carbon
black and hydrogen. Carbon black is used as
a filler for rubber, whereas hydrogen is used
in ammonia synthesis.
9.Coal gas is attained from to a process
carried out at
a) 300oC
b) 700oC
c) 900oC
d) 1300oC

Answer: d
Explanation: Coal gas is produced by heating
the coal at 1300oC when there is a lack of air.
It is usually done in coke ovens or gas
making retorts. This gas is colorless and is
lighter than air.

10.Oil gas is obtaining by the cracking of
a) Kerosene oil
b) Diesel oil
c) Heavy oil
d) Gasoline
Answer: a
Explanation: Creating oil gas is a permanent
process. This is done by breaking of complex
hydrocarbons of kerosene into simpler forms.
This process is known as cracking. Oil finds
its application as a laboratory gas.
11.Which of these gases is used for heating
open-hearth furnaces?
a) Oil gas
b) Producer gas
c) Biogas
d) Water gas
Answer: b
Explanation: Producer gas is known as a
combination of combustible gases, carbon
monoxide, and hydrogen. This gas finds its
application in the heating of open-hearth
furnaces, muffle furnaces, and retorts used in
the production of coke. Also, it can be used as
a reducing means in metallurgical practices.
12.A process of production of water gas is
carried out at
a) 140-200oC
b) 200-400oC
c) 650-750oC
d) 900-1000oC
Answer: d
Explanation: Water gas is formed by
allowing steam and air to flow through hot
coal and coke alternatively. This is
maintained at about 900-1000oC in a steel
vessel reactor. This gas is used a source of
hydrogen and fuel gas, as well as an
illuminating gas.
13.How is biogas prepared?
a) Decantation
b) Filtration
c) Fermentation
d) Sublimation
Answer: c
Explanation: Biogas is a cheap and
convenient fuel used for cooking and for
lighting. It is prepared by the anaerobic
fermentation of cattle dung.

MANUFACTURE OF SYNTHETIC PETROL (BERGIUS PROCESS)

1.Which type of coal is used in Bergius
process?
a) Anthracite coal
b) Steam coal
c) Pulverised coal
d) Gas coal
Answer: d
Explanation: Bergius process is used to
produce synthetic gasoline form low ash
pulverised coal. This coal is finely divided
into powder and is converted into a paste.
2.Which substance is mixed with the
pulverised coal in the Bergius process?
a) Sulphuric acid
b) Heavy oil and catalyst
c) Heavy oil
d) Catalyst
Answer: b
Explanation: The paste of pulverised coal is
mixed with a heavy oil and a catalyst. Nickel
oleate is used as a catalyst in this process.
This mixture is then sent to a converter.

3.At what temperature does the Bergius
process is carried out?
a) 200-300 0C
b) 700-800 0C
c) 350-500 0C
d) 0-150 0C
Answer: c
Explanation: The temperature of converter is
set to about 350-500 0C and a pressure of
about 200-250 atmospheres where the paste
of coal meets hydrogen. The Fischer-Tropsch
process is carried out at 200-300 0C.
4.Which product is obtained from the
converter in the Bergius process?
a) Hydrocarbons
b) Olefins
c) Fuel oil
d) Gasoline
Answer: a
Explanation: The combination of hydrogen
with the carbon framework of the coal yields
various hydrocarbons from wax to gases. The
high molecular weight hydrocarbons are
decomposed further at the high temperature
prevailing in the converter giving lower
hydrocarbons.
5.Same catalyst is used for production of oil
in the Bergius process as used in the
production of hydrocarbons.
a) True
b) False
Answer: b
Explanation: For production of gasoline, oils
produced in the first stage of the process are
subjected to further hydrogenation in the
presence of different catalyst. Nickel oleate is
not used for this process.
6.Which compounds are rich in gasoline
obtained from the Bergius process?
a) Tetraethyl lead
b) Ethanol
c) Olefins
d) Aromatic compounds
Answer: d
Explanation: The gasoline obtained from the
Bergius process is rich in aromatic and
branched-chain hydrocarbons. Tetraethyl lead
is an anti-knocking agent which is used for
increasing the octane number.
7.What happens to the middle oil fraction in
the Bergius process?
a) The oil is converted into olefins
b) The oil is converter into paraffin
c) The oil is converted into gasoline
d) The oil is converted into hydrocarbons
Answer: c
Explanation: The middle oil fraction is
subjected to hydrogen in the presence of a
catalyst to produce gasoline. Same process is
carried out in the top fraction of the reactor.
The heavy oil fraction is recycled to make a
paste with a fresh batch of coal powder.
8.Which undesirable compound is present in
gasoline?
a) Sulphur compounds
b) Phosphorous compounds
c) Chloride compounds
d) Magnesium compounds
Answer: a
Explanation: The gasoline obtained by any
process contains some sulphur compounds
and unsaturated hydrocarbons, which get
oxidized and polymerised to gums and
sludge’s. Hence it has to be refined by
chemical processes.
9.How much percentile of sulphuric acid is
treated with gasoline for the removal of its
impurities?
a) 99 %
b) 60 %
c) 80 %
d) 40 %

Answer: c
Explanation: The impure gasoline is treated
with cold 80 % sulphuric acid. This does not
react with paraffin, naphthenes and aromatic
compounds. It reacts with unsaturated
hydrocarbons to produce alcohols and ethers.

10.Removal of gaseous impurities like
methane, ethane, propane and butane from
gasoline is called as
a) Stabilization of gasoline
b) Sweetening of gasoline
c) Doping of gasoline
d) Blending of gasoline
Answer: a
Explanation: The stabilization of gasoline is
achieved by passing the impure gasoline into
a fractionating tower having 49 plates. The
lower plates are heated by steam, while the
gasoline is introduced near the upper plates.

KNOCKING – OCTANE NUMBER – CETANE NUMBER

1.Which of the following compound is
considered for calculating the octane number?
a) n-heptane
b) n-hexane
c) iso-octane
d) iso-butane
Answer: c
Explanation: The octane number of a fuel is
numerically taken as the percentage of isooctane in a mixture of iso-octane and nheptane. The octane number of iso-octane is
100 and of n-heptane is 0.
2.Which of the following compound readily
goes under the process of knocking?
a) 2-ethly butane
b) n-heptane
c) benzene
d) toluene
Answer: b
Explanation: n-heptane is a straight chain
hydrocarbon which knocks readily and hence
its octane number is zero. Presence of straight
chain hydrocarbon in gasoline reduces its rate
of combustion.
3.Which of the following compound is
considered for calculating the cetane number?
a) α-methyl naphthalene
b) n-hexane
c) iso-octane
d) cetane molecule
Answer: d
Explanation: Cetane, C₁₆H₃₄, is a saturated
hydrocarbon that has a very short ignition lag
as compared to any commercial diesel fuel.
Its cetane number is 100. Cetane number is
the percentile of cetane in a mixture of cetane
and α-methyl naphthalene.
4.What should be the cetane number of
middle speed diesel engine?
a) At least 35
b) At least 25
c) At least 65
d) At least 45
Answer: a
Explanation: The cetane number of high
speed diesel engine should be at least 45, that
of middle speed diesel engine should be at
least 35 and that of low speed diesel engine
should be at least 25.
5.The knocking characteristic of gasoline
fuel are expressed in terms of cetane number.
a) True
b) False
Answer: b
Explanation: The knocking characteristics of
diesel fuel are expressed in terms of cetane
number and that of gasoline fuel is expressed
in terms of octane number. The molecule with
the highest octane number has a least cetane
number.

6.Which of the following substance is used
to decrease knocking in diesel fuel?
a) Tetra ethyl lead
b) Benzene
c) Sodium hydroxide
d) Acetone peroxide
Answer: d
Explanation: The knocking in diesel fuel can
be reduced by adding substances like ethyl
nitrite, ethyl nitrate, isoamyl nitrate etc. This
process also increases the cetane number of
diesel fuel.
7.Which of the following is used to reduce
the surface tension in diesel fuel?
a) Chemical additives
b) Inhibitors
c) Poly hydrocarbon
d) Dopes
Answer: a
Explanation: Chemical additives are used to
reduce surface tension thus promoting the
formation of finer spray. Inhibitors are used to
delay or prevent gum formation. Poly
hydrocarbons are used to preserve the fluid
properties.
8.By which process does the knocking starts
in diesel engine?
a) Due to sudden spontaneous combustion of
last portion of fuel
b) Due to delay in spontaneous combustion of
last portion of fuel
c) Due to the rise in temperature of diesel
engine
d) Due to the parts of diesel engine
Answer: b
Explanation: Due to the presence of
impurities in diesel, its spontaneous
combustion of the last portion of fuel takes
some time. Due to this their produces an
uneven sound in the engine which is called
knocking.
9.Which of the following exhaust gas
produces least harmless components after its
combustion?
a) Carbon monoxide
b) Ethyne
c) NOx
d) N₂
Answer: d
Explanation: Gases produced by the
compression ignition engines are said to be
exhaust gases. This engines operate with airfuel ratios of 14:1 on load and 70:1 on idling.
10.Which of the following has the highest
cetane number?
a) n-heptane
b) n-hexane
c) n-pentane
d) n-butane
Answer: a
Explanation: n-heptane has maximum
branched atom due to which it has the highest
cetane number of all. This fuel is good for
diesel engines.

DIESEL OIL

1.For best results of efficient combustion,
high speed diesel engines need an
approximate cetane number of
a) 100
b) 10
c) 50
d) 5
Answer: c
Explanation: None.
2.Calorific value of diesel oil is of the order of
a) 3000 kcal/kg
b) 5000 kcal/kg
c) 7500 kcal/kg
d) 10000 kcal/kg

Answer: d
Explanation: None

3.Carbon residue in diesel oil should not be more than
a) 1%
b) 0.5%
c) 0.1%
d) 0.01%
Answer: c
Explanation: None.
4.The most popular firing order in case of
four cylinder in-line I.C. engine is
a) 1-2-3-4
b) 1-3-2-4
c) 1-4-2-3
d) 1-3-4-2
Answer: d
Explanation: None.
5.The compression ratio of motor cars is
a) 5
b) 7
c) 10
d) 13
Answer: b
Explanation: None.
6.The specific gravity of diesel oil is
a) 1
b) 0.7
c) 0.85
d) 0.5
Answer: c
Explanation: None.
7.Freezing temperature of petrol is about
a) 0.65
b) 0.75
c) 0.85
d) 0.95
Answer: b
Explanation: None.
8.Choose the correct statement, detonation
can be controlled by
a) varying compression ratio
b) using lean mixture
c) retarding the spark timing
d) reducing the r.p.m
Answer: c
Explanation: Detonation can be controlled
by retarding the spark timing.
9.The efficiency of I.C. engines normally is
of the order of
a) 15-20%
b) 20-25%
c) 25-30%
d) 30-35%
Answer: d
Explanation: None.
10.The firing order of a six stroke I.C. engine is
a) 1-3-6-5-2-4
b) 1-4-2-5-6-3
c) 1-6-2-5-4-3
d) 1-5-3-4-2-6
Answer: d
Explanation: The firing order of a six stroke
I.C. engine is 1-5-3-4-2-6 and firing order in
case of four cylinder in-line I.C. engine is 1-
3-4-2.
11.Sulphur content in diesel engine oil
should not be more than
a) 10%
b) 5%
c) 1%
d) 0.1%
Answer: c
Explanation: None.
12.The ash content in diesel oil should be not
be more than
a) 1%
b) 5%

c) 0.1%
d) 0.01%
Answer: d
Explanation: The ash content in diesel oil
should be not be more than 0.01% while
sulphur content in diesel engine oil should not
be more than 1%.

NATURAL GAS

1.Which of the following is a disadvantage
of gaseous fuel?
a) Gaseous fuels are very difficult to operate
b) Gaseous fuels are highly inflammable
c) Gaseous fuels cannot be ignited instantly
d) They produce lot of smoke on combustion
Answer: b
Explanation: The particles in gaseous fuels
are separated from each other, due to which
their combustion becomes very easy. This
increases the inflammability of the gaseous
fuel. Special care should be taken to avoid
fire hazards.
2.Which of the following is a major
advantage of gaseous fuel over liquid and
solid fuel?
a) Gaseous coal does not form ash
b) Gaseous coal can be manufactured at a
central place
c) Oxidising and reducing atmospheres can be
easily maintained
d) They are economic than solid and liquid
fuels
Answer: a
Explanation: Ash content is present in the
fuel itself. Due to the presence of ash content
in solid and liquid fuels, its rate of
combustion decreases. Also, a lot of smoke is
generated due to the presence of ash content.
3.Which of the following is a primary
gaseous fuel?
a) Water gas
b) Oil gas
c) Refinery gas
d) Liquefied petroleum gas
Answer: d
Explanation: Primary gaseous fuel are those,
which are already present in nature and
secondary gaseous fuels are those which are
obtained from primary gaseous fuels. Natural
gas is also a primary gaseous fuel.
4.Which of the following compound is
present in natural gas?
a) Urea
b) Benzoyl peroxide
c) Methane
d) Sulphonic acid
Answer: c
Explanation: Natural gas is mainly
composed of methane and small quantities of
ethane and other hydrocarbons. Urea consists
of nitrogen due to which it is not present in
natural gas.
5.Which type of natural gas is called wet
natural gas?
a) Containing lower hydrocarbon with more
ethane
b) Containing higher hydrocarbon with more
ethane
c) Containing lower hydrocarbon with more
methane
d) Containing higher hydrocarbon with more
methane
Answer: d
Explanation: If higher hydrocarbons are
present along with methane, then the natural
gas is called “Rich” or “Wet” natural gas. It is
also called “Marsh gas” because it majorly
contains methane.
6.From which of the following natural gas is
majorly obtained?
a) From oil fields
b) From coal fields

c) From seas
d) From sun
Answer: a
Explanation: Most of the natural gas used as
fuel is derived from oil fields. However,
sometimes, the gas is evaporated from the oil
and diffused through rocks, is trapped by
impervious dome shaped structure.

7.Which of the following natural gas has the
highest ignition temperature?
a) Natural gas obtained from oil fields
b) Natural gas obtained from coal fields
c) Natural gas obtained from rocks
d) Natural gas obtained from sea
Answer: c
Explanation: The natural gas produced from
rocks by the diffusion of oil constituents a gas
field that may be under high pressure. Due to
this high pressure, the flow potential of gas
increase, which produces static electricity and
increases the ignition temperature which is
hazardous for us.
8.How much percentile of propane is present
in natural gas?
a) 5.5 %
b) 3.7 %
c) 1.8 %
d) 0.5 %
Answer: b
Explanation: At an average 88.5 % of
methane is present in natural gas. 5.5 % of
ethane, 3.7 % of propane and 1.8 % of butane
are present in natural gas. The higher
hydrocarbons are present at about 0.5 %.
9.H₂S is not present in natural gas.
a) True
b) False
Answer: b
Explanation: H₂S is present in small quantity
in natural gas. If it is present in an appreciable
amount, then it is called as “Sour” natural
gas. At the maximum 15 % of H2S in found
in natural gas till now.
10.Which of the following process is used to
recover vapours of liquid hydrocarbons in wet
natural gas?
a) Evaporation
b) Distillation
c) Cracking
d) Adsorption
Answer: d
Explanation: The vapours of liquid
hydrocarbons can be recovered by
condensation, absorption in oil and by
adsorption on charcoal, silica or alumina gel.
The liquid so recovered is called casinghead
gasoline.

COMPRESSED NATURAL GAS (CNG)

1.Gaseous fuel is most suited for IC engine
since physical delay is almost
a) zero
b) more
c) less
d) none of the mentioned
Answer: a
Explanation: As compared to other fuels
there is almost no delay in gaseous fuel and
for this purpose it is preferred the most.
2.Advantage of hydrogen as an IC engine
fuel
a) high volumetric efficiency
b) low fuel cost
c) no HC and CO emissions
d) none of the mentioned
Answer: c
Explanation: The main advantage of
hydrogen as an IC engine fuel is that there is
no HC and CO emissions.

3.Disadvantage of hydrogen as a fuel in IC
engine is
a) storage is safe
b) low NOx
c) detonating tendency
d) easy handling
Answer: c
Explanation: None.
4.Major constituent of natural gas is
a) ethane
b) methane
c) butane
d) propane
Answer: b
Explanation: Only methane is the major
constituent of natural gas.

5. Octane of natural gas is

a) 60-80

b) 80-100

c) >100

d) <60

Answer: c

Explanation: The octane number of natural gas is always > 100.

6.Major disadvantage of LPG as fuel in
automobiles is
a) reduction in life of engine
b) less power compared to gasoline
c) all of the mentioned
d) none of the mentioned
Answer: c
Explanation: None.
7.Hydrogen gas has selfignition temperature.
a) very low
b) very high
c) no
d) none of the mentioned
Answer: b
Explanation: None.
8.The energy content of air hydrogen mixture
is than liquid hydrocarbon fuels.
a) lower
b) higher
c) negligible
d) none of the mentioned
Answer: a
Explanation: None

LIQUEFIED PETROLEUM GASES (LPG)

1.At normal ambient temperature and
atmospheric pressure, in which form LPG is
obtained?
a) Solid
b) Gaseous
c) Liquid
d) Solid-liquid
Answer: b
Explanation: LPG is a certain mixture of
light hydrocarbons derived from petroleum.
At normal temperature and pressure it is in
gaseous state and later on it is condensed to
the liquid state by the application of moderate
pressure.
2.Under which compound name does the
liquid petroleum gas (LPG) are sold?
a) Urea
b) Ethylene
c) Benzoyl peroxide
d) Butane
Answer: d
Explanation: Propane and butane are present
in the largest amounts in LPG. Small
quantities of ethane, pentane, ethylene and
pentene are also present. Under trade names it
is represented as HP, Bharat gas and Indian
gas in India.

3.By which process only saturated
hydrocarbons are obtained in LPG?
a) Straight distillation
b) Thermal Cracking
c) Hydrocracking
d) Reforming
Answer: a
Explanation: The LPG obtained from heavier
hydrocarbons by straight distillation process
only contains saturated hydrocarbons, where
as the LPG obtained from Thermal cracking
or hydrocracking contains both saturated and
unsaturated hydrocarbons.
4.Which type of LPG is mostly produced in
Indian refineries?
a) Grade A
b) Grade B
c) Grade C
d) Grade D
Answer: b
Explanation: According to the Bureau of
Indian Standards, grade B contains a mixture
of butane and propane. This type of LPG are
supplied for domestic uses.
5.According to the Bureau of Indian
Standards which type of LPG only contains
butane in them?
a) Grade A
b) Grade B
c) Grade C
d) Grade D
Answer: a
Explanation: Grade A consist predominantly
of butanes, butylene or mixture of butanes
and butylene’s. This type of LPG are most
suitable for use due to their moderate rate of
combustion.
6.In which regions does the LPG containing
propane are found?
a) Hotter region
b) Monsoon region
c) Colder region
d) Terrestrial region
Answer: c
Explanation: LPG containing propane is
found in the colder region due to less
temperature and pressure conditions. These
are found towards the north pole of the earth.
7.Liquid petroleum gas (LPG) is corrosive to
steel.
a) True
b) False
Answer: b
Explanation: The sulphur and phosphorous
content in LPG are very low due to which
these are non-corrosive to steel. This type of
fuel is used in industries having large steel
supplies.
8.What happens when LPG is inhaled in
large concentrations?
a) It kills a person
b) It increases a person’s eye sight
c) It does not have any effect on person’s
health
d) It causes a little anaesthesia
Answer: d
Explanation: Butane and propane are present
in large amount are LPG. If inhaled in large
quantities, it becomes anaesthetic which can
cause a person to fall after some time.
9.What is the odour of Liquid Petroleum Gas (LPG)?
a) It is odourless
b) Fruity smell
c) Undesirable odour
d) Alcoholic smell
Answer: a
Explanation: LPG does not have a characteristic odour. Highly odorous compounds such as ethyl and propyl merchants are deliberately mixed so as to help in the detection of any accidental leakage.

10.In which type of industries LPG is used as a fuel?
a) Steel industries
b) Plastic Industries
c) In the production of olefins
d) In the production of coal gas
Answer: c
Explanation: LPG is used as a feedstock for
the manufacturing of olefins by the process of
pyrolysis. It is also used as a domestic fuel for
internal combustion engines.

POWER ALCOHOL AND BIODIESEL.
COMBUSTION OF FUELS: INTRODUCTION

1.Power alcohols contains
a) 50-60% of petrol
b) 70-80% of petrol
c) 50-60% of ethanol
d) 70-80% of ethanol
Answer: b
Explanation: When ethyl alcohol is used in
internal combustion engines then it is called
as power. So, it contains 70-80% of petrol and
20-25% of ethanol.
2.Alcohol can absorb
a) traces of water
b) traces of impurities
c) traces of dust
d) traces of carbon
Answer: a
Explanation: Alcohol has the power to
absorb the traces of water present in petrol as
it dissolves in water.
3.Ethyl alcohol reduces the
a) oxygen emissions
b) efficiency
c) polluting emissions
d) nitrogen emissions
Answer: c
Explanation: Ethyl alcohol contains nascent
oxygen atoms that reduce the pollutants like
CO and other hydro carbons.
4.Power alcohol is than petrol.
a) bad product
b) less efficient
c) costlier
d) cheaper
Answer: d
Explanation: Power alcohol is cheaper than
petrol. It is the main advantage of the power
alcohols made them to be fuels.
5.Main disadvantage of the power alcohol is
a) starting troubles
b) more cost
c) increases foreign currency
d) increases octane number of petrol
Answer: a
Explanation: The main disadvantages of the
power alcohols are starting troubles due to the
high surface tension and atomization.
6.What is the colour of the bio diesel?
a) orange
b) light yellow
c) dark orange
d) light brown
Answer: b
Explanation: The bio diesel is light yellow in
colour. Most of the power alcohols are yellow
in colour as they are hydrocarbons.
7.The natural gas along with the petroleum is
called
a) water gas

b) oil gas
c) wet gas
d) heavy oil
Answer: c
Explanation: The natural gas along with the
petroleum is called as wet gas and water gas
is the mixture of the CO and water.

8.The calorific value of the natural gas is?
a) 1200-1400kcal/m3
b) 500-800kcal/m3
c) 800-900Kcal/m3
d) 12000-14000kcal/m3
Answer: d
Explanation: 12000-14000kcal/m3 is the
calorific value of the natural gas which is
very high value and produces a lot of heat.
9.Natural gas contains
a) methane=70-90%
b) benzene=40-30%
c) hydrogen=50%
d) methane=80-40%
Answer: a
Explanation: The composition of natural gas
is: methane=70-90%; benzene=5-10%;
CO+Carbon dioxide=remainder.
10.The calorific value of LPG is
a) 34800kcal/m3
b) 84000kcal/m3
c) 278000kcal/m3
d) 29000kcal/m3
Answer: c
Explanation: The calorific value of the LPG
is more than that of the natural gas. It is about
278000kcal/m3
. So, it is more efficient than
the natural gas.
11.CNG is stored at a pressure of
a) 281-621kg/cm2
b) 482-591kg/cm2
c) 200-248kg/cm2
d) 800-828kg/cm2
Answer: c
Explanation: CNG is very light weight gas.
So, the storage of the gas is little difficult. So,
it is stored at a pressure of 200-248kg/cm2
.
12.Boiling point of LPG is
a) 546k
b) 373k
c) above room temperature
d) below room temperature
Answer: d
Explanation: LPG has the property of fast
ignition and it needs very less amount of
energy to burn that is the heat supplied is very
low about the temperature less than that if
room temperature.
13.CNG has high auto-ignition temperature of
a) 813k
b) 993k
c) 1163k
d) 1273k
Answer: a
Explanation: CNG also have high auto
ignition energy and has a calorific value of
900 kJ/mole. Its auto ignition temperature is
about 813k.

CALORIFIC VALUE

1.Which of the following statements is
correct?
a) 1k.Cal=2B.Th.U
b) 1B.Th.U=252Cal
c) 1k.Cal=100Cal
d) 1k.Cal=4C.H.U

Answer: b
Explanation: 1B.Th.U=252Cal is the correct one. 1k.Cal=2B.Th.U is wrong because 1k.Cal=3.968B.Th.U=2.2 C.H.U. So 1k.Cal=4C.H.U is also wrong. Kilo means 1000.So, 1k.Cal=1000Cal.

2.To calculate HCV of the fuel, the products
of combustion are cooled down to
a) 600F
b) 700F
c) 400F
d) 200F
Answer: a
Explanation: The products of combustion are
cooled down to 600F or 150C that is room
temperature. The hydrogen gas gets converted
into steam.
3.When the coal is completely burnt in air,
then the maximum temperature reached is
called
a) calorific value of coal
b) gross calorific value
c) calorific intensity of coal
d) net calorific value

Answer: c
Explanation: Calorific value of coal is
defined as the amount of heat liberated during
combustion of fuel completely. Gross
calorific value or HCV means the total heat
liberated after combustion of fuel and

products must be cooled. Net calorific value
is the total heat liberated after combustion of
fuel and products are allowed to escape. So,
the maximum temperature reached is calorific
intensity of coal.

4.To calculate the net calorific value, the
products are
a) cooled
b) allowed to escape
c) heated
d) collected

Answer: b
Explanation: The products in finding NCV
are allowed to escape as the hot gases has no
chance of condensation. Cooled in HCV.

5.The Bomb calorimeter is used to determine
the calorific value of
a) solids and liquid fuels
b) solid and gaseous fuels
c) liquid fuels that can be easily vaporized
d) solid fuels only
Answer: a
Explanation: In Bomb calorimeter, we can
find the calorific value of both solid and gas
fuels. In Boy’s calorimeter we can fin
calorific value for gaseous and easily
vaporized liquid fuels.
6.The calorific value of LPG is generally
than that of coal.
a) higher
b) lower
c) half
d) very lesser
Answer: a
Explanation: Generally, the calorific values
of liquid fuels are more than that of solid
fuels. They produce more heat than liquid.
So, the calorific value of LPG is more than
that of coal.

7.If there is more oxygen content in fuel,
then the calorific value of the fuel is

a) high
b) low
c) moderate
d) very high
Answer: b
Explanation: The oxygen content in fuel will
reduce its ability to burn and so that it cannot
produce more amount of heat. So, the
calorific value will be low.

8.Which of the following fuel gas will have
the highest calorific value?
a) Water gas
b) Bio gas
c) Producer gas
d) Natural gas
Answer: d
Explanation: Natural gas produces a high
amount of heat when compared to the other
three gases. Water gas and producer gas are
synthetic fuels and natural gas natural fuel.

HIGHER AND LOWER CALORIFIC VALUESTHEORETICAL CALCULATION OF CALORIFIC VALUE

1.On which property of fuel it’s calorific
value is based?
a) Specific heat
b) Efficiency
c) Cost
d) Ignition temperature
Answer: b
Explanation: The calorific value is the total
amount of heat liberated by complete
combustion a unit amount of fuel, which is
the total efficiency of the fuel.
2.What is the unit of calorific value in
fps(foot pound sec)?
a) Gram calorie (g cal)
b) Pound calorie
c) British thermal unit/ft3
d) Calorie/gram2
Answer: b
Explanation: B.T.U. is the amount of heat
required to rise the temperature of 1 lb of
water through 1 0F. Centigrade heat unit
(CHU) can also be used in fps system.
3.At how much temperature does the
products of combustion should be cooled
down to get Gross Calorific Value?
a) 288 K
b) 315 K
c) 390 K
d) 350 K
Answer: a
Explanation: At 288 K the products are
cooled down, so as to get exact gross calorific
value. It can be cooled down till room
temperature.
4.What happens to the hydrogen present in
fuel for calculating gross calorific value?
a) It combines with carbon to form methane
b) It combines with chlorine to form
hydrochloric acid
c) It combines with oxygen to form hydrogen
per oxide
d) It gets converted into steam
Answer: d
Explanation: After combustion of hydrogen,
it gets converted into water vapour which
then settles down as steam. After this process
the products of combustion are cooled down.
5.How does the latent heat of condensation is
included in gross calorific value?
a) By the steam produced by the combustion
of hydrogen
b) By the combustion of products other than
carbon and hydrogen
c) By the combustion of carbon
d) By the total heat produced in the system
Answer: a
Explanation: The steam generated after
combustion gets condensed into water and
latent heat is evolved. The latent heat so
liberated is included in gross calorific value.

6.What’s the basic formulae for calculating
gross calorific value?
a) [8080 %C + 3450(%H – %O⁄8) + 2240 %S]⁄100 cal/gm
b) [8080 %C + 34500(%H – %O⁄24) + 2240 %S]⁄100 cal/gm
c) [8080 %C + 34500(%H – %O⁄16) + 2240 %S]⁄100 cal/gm

d) [8080 %C + 34500(%H⁄1 – %O⁄8) + 2240
%S]⁄100 cal/gm

Answer: d
Explanation: This formulae is also called as
Dulong’s formula. With the help of
%C,%H,%O and %S present in fuel gross
calorific value can be calculated.

7.Net Calorific Value is greater than Gross
Calorific Value.
a) True
b) False
Answer: b
Explanation: NCV = [GCV – 0.09%H×587]
cal/gm, since both GCV and % H are positive
the value of NCV will be less than GCV.
8.Which of the following properties a good
fuel should have?
a) Low Calorific value
b) Moderate Calorific value
c) High Calorific value
d) High ignition temperature
Answer: c
Explanation: Calorific value is the total
amount of heat liberated by complete
combustion of fuel, therefore the more the
calorific value will be, the good the fuel will
be.
9.Which of the fuel has the highest calorific
value?
a) Butane
b) Wood
c) Kerosene
d) Natural gas
Answer: a
Explanation: The calorific value of butane is
118 MJ/kg, this is due to the saturation of
carbon bonding in butane, where as the
calorific value of wood is lowest which is 16
MJ/kg.

IGNITION TEMPERATURE

1.A good fuel should possess calorific value.
a) high
b) low
c) very low
d) moderate
Answer: a
Explanation: Calorific value is the total
amount of heat liberated on combustion of
unit mass or unit volume of fuel in the
presence of air or oxygen. A good fuel should
possess high calorific value since the amount
of heat liberated and the temperature attained
thereby depends upon this property of a fuel.
2.How should be the ignition temperature of
an ideal fuel?
a) moderate
b) low
c) very low
d) very high
Answer: a
Explanation: The lowest temperature to
which the fuel must be preheated so that it
starts burning smoothly is called ignition
temperature. Low ignition temperature can
cause fire hazards during storage and
transportation of fuel. In case of high ignition
temperature, there might be some difficulty
during ignition of fuel. So, an ideal fuel
should have moderate ignition temperature.
3.Fuel should have low moisture content.
a) true
b) false
Answer: a
Explanation: Moisture if present in the fuel, reduces the heating value of the fuel. This ultimately leads to loss of money as moisture is paid at the same rate as that of fuel. Hence,an ideal fuel should have low moisture content.

4.In which type of fuel given below, risk of
fire hazard is greatest?
a) Solid fuel
b) Gaseous fuel
c) Liquid fuel
d) Peat
Answer: b
Explanation: Risk of fire hazards in gaseous
fuel is very high because these fuels are
highly inflammable. Peat is a type of solid
fuel.
5.is easy in terms of storage.
a) Solid fuel
b) Liquid fuel
c) Gaseous fuel
d) Natural gas
Answer: a
Explanation: Solid fuel is easy to store.
Liquid fuel should be stored in closed
containers only. Gaseous fuel must be stored
in leak proof storage tanks. Natural gas is a
type of gaseous fuel.
6.Rate of combustion should be
a) Very rapid
b) Moderate
c) Slow
d) Very slow
Answer: b
Explanation: If the rate of combustion is low,
then a part of heat liberated may get radiated
instead of raising the temperature. If
combustion rate is too high, reaction gets out
of control. So, good fuel should have
moderate rate of combustion.
7.Handling cost of solid fuel is high
compared to liquid and gaseous fuel.
a) True
b) False
Answer: a
Explanation: Handling cost of solid fuel is
high because labour is required in their
storage, transport, etc. Whereas liquid and
gaseous fuel can be easily transported through
pipes.
8.The lowest temperature to which the fuel
must be preheated so that it starts burning
smoothly is called temperature.
a) Ignition
b) Combustion
c) Boiling point of fuel
d) Preheating
Answer: a
Explanation: The lowest temperature to
which the fuel must be preheated so that it
starts burning smoothly is called ignition
temperature. An ideal fuel should have
moderate ignition temperature.
9.Which of the following fuel cannot be used
in the internal combustion engine?
a) gasoline
b) diesel
c) fuel oil
d) anthracite coal
Answer: d
Explanation: Anthracite is a type of solid
fuel. It is not possible to use solid fuel in
internal combustion engine. Only liquid or
gaseous fuels are possible to be used in the
internal combustion engine.
10.In which of the following, smoke is
produced maximum?
a) Solid fuel
b) Liquid fuel
c) Gaseous fuel
d) Coal gas
Answer: a
Explanation: In solid fuel, smoke is invariably produced. In liquid fuel burning is clean however high carbon and aromatic liquid fuels may produce smoke. Smoke is not produced in gaseous fuels.

SPONTANEOUS IGNITION TEMPERATURE

1.The rating of a diesel engine, with increase
in air inlet temperature, will
a) increase linearly
b) decrease linearly
c) increase parabolically
d) decrease parabolically
Answer: b
Explanation: None.
2.The knock in diesel engine occurs due to
a) instantaneous and rapid burning of the first
part of the charge
b) instantaneous auto ignition of last part of
charge
c) reduction of delay period
d) none of the mentioned
Answer: a
Explanation: None.
3.Volatility of diesel fuel is
a) maximum temperature to which oil is
heated in order to give off inflammable
vapour in sufficient quantity to ignite
momentarily when bought in contact with a
flame
b) it catches fire without external aid
c) indicated by 90% distillation temperature
d) none of the mentioned
Answer: c
Explanation: None.
4.Violent sound pulsations within the
cylinder of an I.C. engine are caused due to
a) heavy turbulence
b) improved scavenging
c) detonation
d) pre-ignition
Answer: c
Explanation: None.
5.Auto-ignition temperature is
a) maximum temperature to which oil is
heated in order to give off inflammable
vapour in sufficient quantity to ignite
momentarily when bought in contact with a
flame
b) that at which it catches fire without
external aid
c) indicated by 90% distillation temperature
d) none of the mentioned
Answer: b
Explanation: Auto-ignition temperature is
defined as that temperature at which it
catches fire without external aid while
volatility of diesel fuel is indicated by 90%
distillation temperature.
6.Ignition lag is
a) the time taken by fuel after injection to
reach upto auto-ignition temperature
b) time before actual fuel injection and the
pump plinger starts to pump fuel
c) time corresponding to actual injection and
top dead center
d) none of the mentioned
Answer: a
Explanation: None.
7.The delay period in petrol engine is of the
order of
a) 0.001 sec
b) 0.002 sec
c) 0.01 sec
d) 0.1 sec
Answer: b
Explanation: None.
8.Detonation is caused by the following
unstable compounds
a) peroxides, aldehydes and ketones
b) peroxides, aldehydes, oxides and sulphides

c) aldehydes, oxides and ketones
d) none of the mentioned
Answer: a
Explanation: Detonation is caused by
peroxides, aldehydes and ketones.

9.In order to prevent knock in the S.I.
engines, the charge away from the spark plug
should have
a) low temperature
b) low density
c) rich mixture
d) all of the mentioned
Answer: d
Explanation: None.
10.To reduce the possibility of knock in C.I.
engines, the first elements of fuel and air
should have
a) high temperature
b) high density
c) short delay
d) all of the mentioned
Answer: d
Explanation: None.
11.The detonation tendency in petrol engines
for specified conditions of fuel rating,
compression ratio, speed etc, can be
controlled by having
a) smaller cylinder bore
b) bigger cylinder bore
c) medium cylinder bore
d) none of the mentioned
Answer: a
Explanation: None.
12.A fuel will detonate less if it has
a) higher self ignition temperature
b) lower self ignition temperature
c) proper self ignition temperature
d) none of the mentioned
Answer: a
Explanation: None.
13.Ignition quality of diesel fuel oil is
expressed by an index called.
a) octane number
b) cetane number
c) calorific value
d) none of the mentioned
Answer: b
Explanation: Cetane number is defined as the
ignition quality of diesel fuel oil is expressed
by an index.

EXPLOSIVE RANGE

1.In presence of which gas is the fuel burnt
to generate energy in the form of heat?
a) Oxygen
b) Hydrogen
c) Methane
d) Nitrogen
Answer: a
Explanation: The fuel is burnt in the
presence of oxygen to generate energy in the
form of heat. This heat energy can be used for
electrical power generation in steam power
plants and for propelling ships, automobiles
and locomotives, etc.
2.Which are the main constituents of fuel
from given options?
a) Carbon and Nitrogen
b) Oxygen and Hydrogen
c) Carbon and Hydrogen
d) Helium and Oxygen
Answer: c
Explanation: Carbon and Hydrogen are the main constituents of a fuel. In addition to them, fuel also contains sulfur, oxygen and nitrogen in minimal quantities. Depending on the fuel, the percentage of carbon ranges from 50-95%, hydrogen (H₂) 2-6%, oxygen (O₂) 2-4%, sulfur (S₂) 0.5-3% and Nitrogen (N) 5- 7%. A solid fuel may also contain 2 30% ash. In a fuel carbon, hydrogen and sulfur are combustible elements whereas nitrogen and ash are incombustible elements. Since the major combustible elements in fuel are carbon and hydrogen it can also be called as Hydrocarbon fuel.

3.Which fuel is used widely in steam power
plants?
a) Oil
b) Gas
c) Coal
d) Petroleum
Answer: c
Explanation: Coal is the oldest form of fuel
and is still used in a large scale throughout
the world by steam power plants as well as all
power generation plants. Coal is a
heterogeneous compound and its constituents
are always carbon, hydrogen, oxygen, sulfur,
nitrogen and certain mineral non
combustibles.
4.What is the phenomenon of the formation
of coal called?
a) Metamorphism
b) Diagenis’
c) Photosynthesis
d) Protolith
Answer: a
Explanation: The phenomenon by which the
buried vegetation consisting wood, grass,
shrubs etc, transformed into coal is known as
metamorphism. The nature of coal will
depend upon the type of vegetation buried
and nature and duration of metamorphism.
There are different types of metamorphism
namely contact metamorphism, regional
metamorphism, cataclastic metamorphism,
hydrothermal metamorphism, burial
metamorphism and shock metamorphism.
5.On what basis is the coal classified?
a) Period of formation
b) Depending on capacity to burn
c) Region/area where is it formed
d) Physical and chemical composition
Answer: d
Explanation: The coal is classified on the
basis of its physical and chemical
composition. The proximate and ultimate
analyses are the common tests which are used
to find the commercial value of the coal. The
proximate analysis gives characteristics of
coal such as percentage of moisture, ash and
volatile matter. Analysis of coal gives an
indication about fusion temperature and
heating value of the coal.
6.What is the use of electrostatic
precipitations in steam power plant?
a) To remove the steam
b) To draw the coal powder into boiler
c) To remove the feed water
d) To remove fly ash
Answer: d
Explanation: The electrostatic precipitators
are extensively used in the steam power plant
for removal of fly ash from the electric utility
boiler emission. Since the water inside the
boiler is converted into steam, the fire for
converting is fuelled by burning the coal
which produces high amount of fly ash, so
that the ash’ can be reused. The use of
electrostatic precipitators is growing rapidly
because of the new strict air code and
environmental laws. An electrostatic can be
designed to operate at any desired efficiency.
7.Why is ‘make-up water’ added to drum
continuously?
a) To remove the impurities in tube
b) To replace the water that has been
converted into steam
c) To keep the system cool externally
d) To compensate for water loss trough blow
down
Answer: d
Explanation: Make-up water is added to compensate for the losses of water incurred by blow downs or leakages occurring in boiler, and also to maintain desired water level in boiler steam drum. Blow down and leakages are common since there is continuous flow of condensate from condenser to boiler.

8.What causes failure of boiler tube?
a) Heating the tubes, when desired water level
is not maintained
b) Induced pressure in the water
c) Over use of boiler
d) Hardness of water
Answer: d
Explanation: Hardness of water causes
failure of boiler tube. Hard water consists of
calcium and magnesium salts. Hardness in
water will form deposits on the tube water
surfaces which will lead to overheating and
failure of tubes. Thus the salts have to be
removed from the water.

FLUE GAS ANALYSIS (ORSAT METHOD).

1.Which of the following is the correct
condition for the efficient combustion of
coal?
a) Coal should be of high calorific value
b) Intimate mixing of air with the
combustible matter
c) The ignition temperature should be high
d) The volatile matter should be low
Answer: b
Explanation: For efficient combustion, it is
essential that the coal and its distillation
products are brought into intimate contact
with sufficient quantity of air to burn all
combustible material. Also, sufficient time
should be allowed to complete the
combustion process.
2.Which of the following furnace is best
suitable for the efficient combustion of coal?
a) Blast furnace
b) Pudding furnace
c) Open hearth furnace
d) Boiler furnace
Answer: d
Explanation: This type of furnaces are used
for efficient combustion of coal since these
convert the heat into thermal energy which
are then used for generation of power.
Pudding furnace and open hearth furnaces are
types of steelmaking furnaces.
3.Which of the following is calculated by
flue gas analysis?
a) Amount of air used in combustion
b) Rate of combustion
c) Time required for combustion
d) Amount of air present after combustion
Answer: a
Explanation: The only practical way for
determining the amount of air used in furnace
is to analyse the flue gas for the constituents
CO₂, CO an O₂ . The control of air is by means of dampers.
4.What happens when carbon monoxide is
obtained in flue gas analysis?
a) Combustion is complete
b) Combustion does not take place
c) Combustion is incomplete
d) It increases the rate of combustion.
Answer: c
Explanation: If the analysis shows the
presence of free CO, it means that the
combustion is incomplete which calls for an
intermediate increase in the amount of air
used for combustion. Also, a diminution in
the rate of supply of coal is required.
5.Which of the following compound other
than CO₂, CO an O₂ can be determined by
the flue gas analysis?
a) C₂H₆
b) C₆H₆
c) C₆H₁₁O₂₂
d) Ethylene
Answer: a
Explanation: Sometimes N₂, H₂ and hydrocarbons like CH₄ and C₂H₆ are obtained by flue gas analysis of coal. If N₂ is obtained after the analysis, the combustion will be incomplete.

6.What happens when too much excess air is
supplied to the furnace in the process of
combustion of coal?
a) There is a gain in heat in the furnace
b) No change occurs in the furnace
c) There is loss in heat in the furnace
d) The excess air escapes out
Answer: c
Explanation: In ordinary furnaces, 50 to 100
% excess air is generally supplied. If the
excess air is supplied above this amount,
there is a loss of heat in the furnace. In such
cases, the supply of air to the hearth is cut
short or the rate of fuel supply is increased.
7.If both CO and O₂ , both are indicated in
the appreciable amount in the flue gas
analysis, which type of combustion is seen?
a) Regular and non-uniform combustion
b) Irregular and non-uniform combustion
c) Regular and uniform combustion
d) Irregular and uniform combustion
Answer: b
Explanation: If both CO and O₂ are present
in an appreciable amount, then the
combustion is irregular and non-uniform.
That means, in some parts of the furnace,
there is an excess of air and in some other
parts, the supply of air is insufficient.
8.Short orsat apparatus gives more precise
results than long orsat in the analysis of flue gas.
a) True
b) False
Answer: b
Explanation: Long orsat or precision model
orsat is used for analysis of quite complicated
mixtures and which gives very accurate
results in competent hands. The precision
orsat assemblies are mounted on substantial
stands.
9.At what temperature does the CO is
converted to CO₂ in orsat apparatus for
analysis of flue gas?
a) 280-295 0C
b) 250-265 0C
c) 350-365 0C
d) Less than 100 0C
Answer: a
Explanation: At the temperature range of
280-295 0C, the CO is converted into CO₂.
Also the hydrogen present is oxidised to
water. The diminution in the volume of gas
sample indicates the volume of hydrogen.
10.Which of the following apparatus cannot
be used for flue gas analysis?
a) Ambler’s apparatus
b) Hemple’s apparatus
c) Able’s apparatus
d) Bunte’s apparatus
Answer: c
Explanation: Able’s apparatus is used for
calculation of flash point and fire point of an
oil. Flash point is the minimum temperature
of oil, at which the vapours of oil produces
flash in a burning match stick when brought
close to the vapours of oil.

Prabakaran S

Leave a Reply Cancel reply