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1.
Which of the following creates a flapping
sound near the front of the engine?
2.
An engine noise sounds like a knock at the
side of the engine that is louder when the engine is cold and goes
away or is reduced when the engine reaches operating temperature.
Which of the following is the MOST likely cause?
3.
This question is not like the others. It
has the word EXCEPT. For this question, look for the choice that
could NOT cause the described situation. Read the entire question
carefully before choosing your answer. All of the following are
reasons why you must disable the fuel injection system and ignition
system when conducting an engine compression test,
EXCEPT:
4.
A power balance test is being performed.
Technician A says to note the engine RPM before and during the test
for each cylinder. Technician B says to record the RPM drop for
each cylinder. Who is right?
Cylinder Head and Valve Train Diagnosis and Repair
5.
What engine seal is pictured in the
illustration on the right? (Image courtesy of
Toyota.)
6.
Technician A says the closed coil end of a
valve spring should go against the cylinder head. Technician B says
all valve springs use shims to control free spring height. Who is
right?
7.
This question is not like the others. It
has the word EXCEPT. For this question, look for the choice that
could NOT fit the described situation. Read the entire question
carefully before choosing your answer. All of the following
statements are correct when adjusting valve lash on engines with
overhead camshaft cylinder heads, EXCEPT:
8.
The surface of the cylinder head has just
been machined. What will have to be done to the valve
train?
Engine Block Diagnosis and Repair
9.
A technician hears a knock or thumping at
the side of the engine block that is louder when the engine is hot
and goes away when the affected cylinder is shorted out. Which of
the following could be the cause?
10.
An engine is making a knocking sound that
changes with RPM, and the noise disappears while a cylinder is
being tested during the cylinder balance test. Which of the
following could be the cause?
11.
This question is not like the others. It
has the word EXCEPT. For this question, look for the choice that
could NOT fit the described situation. Read the entire question
carefully before choosing your answer. All of the following are
ways the piston is attached to the rod, EXCEPT:
12.
Technician A says before you remove an
engine assembly, the battery must be disconnected. Technician B
says to assist in reassembly, you should take a photograph of the
engine compartment before you remove any components or connectors.
Who is right?
Lubrication and Cooling Systems Diagnosis and Repair
13.
Technician A says a weak solution of
antifreeze may cause corrosion build-up in the cooling system.
Technician B says some original equipment manufacturers (OEM)
recommend that the coolant be changed at specified intervals. Who
is right?
14.
When refilling a cooling system, which of
the following steps is NOT necessary?
15.
Which of the following indicated a
contaminated cooling system?
16.
The proper coolant freeze protection can be
measured with which of the following tools?
Fuel, Electrical, Ignition and Exhaust Systems Inspection and
Service
17.
A technician is using a laptop computer and
manufacturer software to test the ECT (Electronic Controlled
Throttle) circuit that has a stored DTC P1121 (Electric Throttle
Control Actuator). Which of the following customer concerns could
be caused by a defective ECT return spring
malfunction?
18.
Technician A says the voltage required
maintaining spark is referred to as the spark line and the duration
of the spark line is based on total primary circuit resistance and
coil voltage available. Technician B says problems with the burning
(called fuel propagation) will show up within the spark line. Who
is right?
19.
Low-firing voltages are measured on a shop
oscilloscope and this indicates a lower voltage is required for the
spark to jump the gap. Which of the following is the MOST likely
cause?
20.
Turbochargers use boost pressure to
indicate proper operation. What units are used to measure boost in
the English System of Measurement?
General
Transmission/Transaxle Diagnosis
1.
You are using a diagnostic symptom chart to
diagnose an electronically controlled 5-speed automatic RWD (rear
wheel drive) transmission with a strange noise in drive. Technician
A says the control valve could be the cause and is an OFF-vehicle
procedure. Technician B says the oil pump assembly could be the
cause and is an OFF-vehicle procedure. Who is right?
2.
On an electronically controlled 4-speed
automatic transaxle, you experience a "shock" when shifting from
"N" to "D." Which of the following will require an OFF-vehicle
repair?
3.
Technician A says you pick the symptom in
the on-line service information that closely matches the customer
concern. Technician B says the customer will describe their
concerns as they are listed in the on-line service information. Who
is right?
4.
This question is not like the others. It
has the word EXCEPT. For this question, look for the choice that
could NOT fit the described situation. Read the entire question
carefully before choosing your answer. Preliminary diagnosis on an
electronically controlled automatic transmission/transaxle consists
of all the following tests, EXCEPT:
5.
Technician A says engine, suspension and
driveline problems may appear to be caused by the transmission or
transaxle. Technician B says you start with the simple inspections
first to ensure that you have not overlooked something and you can
use the scan tool for further clarification. Who is
right?
6.
You are checking fluid color on an
automatic transmission/transaxle. Which of the following will cause
the fluid to be varnished with a light to dark brown
color?
7.
If the fluid inspection shows a pinkish
color and indicates water contamination, which coolant system
component is a possible cause?
8.
Technician A says the stall test is
performed to see if the torque converter and internal holding
components operate properly. Technician B says the stall test is
conducted before the line pressure test. Who is
right?
In-Vehicle Transmission/Transaxle Maintenance and Repair
9.
A technician is checking the automatic
transaxle manual valve control cable after an adjustment.
Technician A says to make sure the transaxle is locked properly
when the selector lever is placed in the P position. Technician B
says to make sure that the starter operates only when placed in the
N position.
10.
A technician moves the gear selector lever
from the PARK position to the MANUAL LOW position and cannot hear
the detent and the pointer indicating the gear position is
misaligned. Which of the following could be the
cause?
11.
DTC (Diagnostic trouble code) P0705 PNP
(park/neutral position) switch circuit is being diagnosed.
Technician A says this code sets when the TCM (Transmission Control
Module) or PCM (powertrain control module) does not receive the
correct voltage signal from the park/neutral position (PNP) switch.
Technician B says the park/neutral position (PNP) switch circuit
could be open or shorted. Who is right?
12.
Technician A says low line pressure on an
electronically controlled line pressure can cause the transmission
to slip and operate sluggishly. Technician B says line pressure
varies with engine speed. Who is right?
13.
A line pressure test shows low pressure at
idle in all ranges on an electronically controlled automatic
transmission. Which of the following can be the
cause?
14.
Using the chart on the right to diagnose a
4-speed automatic transaxle, which of the following is the MOST
likely cause of no engine braking in manual second?
15.
The low-reverse band has failed on 4-speed
transmission shown in the chart on the right. Technician A says
there will be no reverse gear. Technician B says you will have all
forward gears in Drive. Who is right?
16.
Two technicians are discussing TV (Throttle
Valve) linkage adjustments. Technician A says electronically
controlled transmissions use a scan tool to adjust the TV cable.
Technician B says that an improperly adjusted TV linkage can cause
early or late shifts. Who is right?
Off-Vehicle Transmission/Transaxle Repair
17.
Technician A says you should rotate the
converter to align the bolt holes with the flexplate after the
transmission has been bolted to the engine. Technician B says a
transmission overhaul is not complete until it passes a road test.
Who is right?
18.
When removing an engine from a vehicle
equipped with an automatic transmission, the torque converter does
which of the following?
19.
A torque converter flex plate is being
inspected. Technician A says to check for loose, misaligned or
missing bolts. Technician B says to check for cracks, especially
around the bolt holes. Who is right?
20.
This question is not like the others. It
has the word EXCEPT. For this question, look for the choice that
could NOT fit the described situation. Read the entire question
carefully before choosing your answer. When inspecting the flex
plate as shown in the photo on the right, you should check it for
all of the following, EXCEPT:
21.
A vehicle PCM requires programming to
resolve a transmission shift problem listed in a service bulletin.
Technician A says reprogramming consists of downloading new
calibration files from a scan tool, personal computer or modem into
the PCM's electronically erasable programmable read-only memory
(EEPROM). Technician B says reprogramming is not an OBD-II
requirement but that many vehicles will need a new PCM in the event
software changes become necessary. Who is right?
22.
This question is not like the others. It
has the word EXCEPT. For this question, look for the choice that
could NOT fit the described situation. Read the entire question
carefully before choosing your answer. All of the following are
industry-standard methods used to reprogram the EEPROM,
EXCEPT:
23.
An automatic transmission pressure test
will identify which of the following?
24.
This question is not like the others. It
has the word EXCEPT. For this question, look for the choice that
does NOT meet the described situation. Read the entire question
carefully before choosing your answer. All of the following actions
are done in the repair of a damaged molded connector in a safety
system, EXCEPT:
IC Engines Q& A
1.The pressure at the end of compression in the case of
diesel engine is of the order of
6 kg/cm
12kg/cmz
20 kg/cmz
27.5 kg/cmz
35 kg/cm
Ans: 35 kr/cm
2.The ratio of indicated thermal efficiency to the
corresponding air standard cycle efficiency is called
net efficiency
efficiency ratio
relative efficiency
overall efficiency
cycle efficiency.
Ans: relative efficiency
3.Compression ratio of LC. engines is
the ratio of volumes of air in
cylinder before compression stroke and after compression stroke
volume displaced by piston per
stroke and clearance volume in cylinder
ratio of pressure after
compression and before compression
swept volume/cylinder volume
cylinder volume/swept
volume.
Ans: the ratio of volumes of air in cylinder before
compression stroke and after compression stroke
4.Supercharging is the process of
supplying the intake of an
engine with air at a density greater than the density of the
surrounding atmosphere
providing forced cooling air
injecting excess fuel for
raising more load
supplying compressed air to
remove combustion products fully
raising exhaust pressure.
Ans: supplying the intake of an engine with air at a
density greater than the density of the surrounding atmosphere
5.The specific fuel consumption per BHP hour for diesel
engine is approximately
0.15 kg
0.2 kg
0.25 kg
0.3 kg
0.35 kg.
Ans: 0.2kg
6.The temperature of interior surface of cylinder wall
in normal operation is not allowed to exceed
80�C
120�C
180�C
240�C
320�C.
ANSWER : :
180�C
7.In a diesel engine, the fuel is ignited
by
spark
injected fuel
heat resulting from compressing
air that is supplied for combustion
ignitor
combustion chamber.
ANSWER : : heat resulting from compressing air that is
supplied for combustion
8.The air standard efficiency of an Otto cycle compared
to diesel cycle for the given compression ratio is
same
less
more
more or less depending on power
rating
unpredictable.
ANSWER : : more
9.If the compression ratio of an engine working on Otto
cycle is increased from 5 to 7, the %age increase in efficiency
will be
2%
4%
8%
14%
27%.
ANSWER : : 14%
10.All heat engines utilize
low heat value of oil
high heat value of oil
net claorific value of oil
calorific value of fuel
all of the above.
ANSWER : : low heat value of oil
11.The maximum temperature in the I.C. engine cylinder
is of the order of
500- 1000�C
1000- 1500�C
1500-2000�C
2000-2500�C
2500-3000�C
ANSWER : :
2000-2500�C
12.The calorific value of gaseous fuels is expressed in
terms of
kcal
kcal/kg
kcal/m2
kcal/n?
all of the above.
ANSWER : : kcal/n?
13.Pick up the wrong statement
2-stroke engine can run in any
direction
In 4-stroke engine, a power
stroke is obtained in 4-strokes
thermal efficiency of 4-strokc
engine is more due to positive scavenging
petrol engines work on to
cycle
petrol engines occupy more
space than diesel engines for same power output.
ANSWER : : petrol engines occupy more space than diesel
engines for same power output.
14.The thermal efficiency of a diesel cycle having fixed
compression ratio, with increase in cut-off ratio will
increase
decrease
be independent
may increase or decrease
depending on other factors
none of the above.
ANSWER : : decrease
15.In a typical medium speed 4-stroke cycle diesel
engine the inlet valve
opens at 20� before top dead
center and closes at 35� after the bottom dead center
opens at top dead center and
closes at bottom dead center
opens at 10� after top dead
center and closes 20� before the bottom dead center
may open or close anywhere
remains open for 200�.
ANSWER : : opens at 20�before top dead center and closes at
35�after the bottom dead
center
16.Fuel oil consumption guarantees for I .C. engine are
usually based on
low heat value of oil
high heat value of oil
net calorific value of oil
calorific value of fuel
all of the above.
ANSWER : : high heat value of oil
17.The fuel in diesel engine is normally injected at
pressure of
5-10 kg/cm2
20-25 kg/cm2
60-80 kg/cm2
90-130 kg/cm2
150-250 kg/cm2
ANSWER : : 90-130 kg/cm2
18.Does the supply of scavenging air at a density
greater than that of atmosphere mean engine is supercharged
?
yes
no
to some extent
unpredictable
depends on other factors.
ANSWER : : no
19.In case of gas turbines, the gaseous fuel consumption
guarantees are based on
high heat value
low heat value
net calorific value
middle heat value
calorific value.
ANSWER : : low heat value
20.The pressure and temperature at the end of
compression stroke in a petrol engine are of the order
of
4 - 6 kg/cm2 and 200 -
250�C
6 - 12 kg/cm2 and 250 -
350�C
12 - 20 kg/cm2 and 350 -
450�C
20 - 30 kg/cm2 and 450 -
500�C
30 - 40 kg/cm2 and 500 -
700�C.
ANSWER : : 6 - 12 kg/cm2 and 250 -
350�C
21.An engine indicator is used to determine the
following
speed
temperature
volume of cylinder
m.e.p. and I.H.P.
BHP.
ANSWER : : m.e.p. and I.H.P.
22.If the intake air temperature of I.C. engine
increases, its efficiency will
increase
decrease
remain same
unpredictable
depend on other factors.
ANSWER : : decrease
23.Scavenging air in diesel engine means
air used for combustion sent
under pres-sure
forced air for cooling
cylinder
burnt air containing products
of com-bastion
air used for forcing burnt
gases out of engine's cylinder during the exhaust period
air fuel mixture.
ANSWER : : air used for forcing burnt gases out of
engine's cylinder during the exhaust period
24.Combustion in compression ignition engines
is
homogeneous
heterogeneous
both (a) and (b)
laminar
turbulent.
ANSWER : : heterogeneous
1.The output of a diesel engine can be increased without
increasing the engine revolution or size in following
way
feeding more fuel
increasing flywheel size
heating incoming air
scavenging
supercharging.
ANSWER : : supercharging.
2.The air-fuel ratio of the petrol engine is controlled
by
fuel pump
governor
injector
carburettor
scavenging.
ANSWER : : carburettor
3.A 75 cc engine has following parameter as 75
cc
fuel tank capacity
lub oil capacity
swept volume
cylinder volume
clearance volume.
ANSWER : : swept volume
4.Which of the following is not an interna combustion
engine
2-stroke petrol engine
4-stroke petrol engine
diesel engine
gas turbine
steams turbine.
ANSWER : : steams turbine.
5.The accunmulation of carbon in a cylinder results in
increase of
clearance volume
volumetric efficiency
ignition time
effective compression ratio
valve travel time.
ANSWER : : effective compression ratio
6.The specific fuel consumption per BH hour for a petrol
engine is approximately
0.15 kg
0.2 kg
0.25 kg
0.3kg
0.35 kg.
ANSWER : : 0.25 kg
7.In diesel engine the diesel fuel injected intc
cylinder would burn instantly at about compressed air temperature
of
250�C
500�C
1000�C
150CPC
2000�C.
ANSWER : :
1000�C
8.It the temperature of intake air in IC engines is
lowered, then its efficiency will
increase
decrease
remain same
increase upto certain limit and
then decrease
decrease upto certain limit and
then in-crease.
ANSWER : : increase
9.Pick up the false statement
Thermal efficiency of diesel
engine i about 34%
Theoretically correct mixture of
air am petrol is approximately 15 : 1
High speed compression engines
operate on dual combustion cycle
Diesel engines are compression
ignition engines
S.I. engines are
quality-governed engines.
ANSWER : : S.I. engines are quality-governed
engines.
10.The air requirement of a petrol engine during
starting compared to theoretical required for complete combustion
is
more
loss
same
may be more or less depending
on engine capacity
unpredictable.
ANSWER : : loss
11.The rating of a diesel engine, with increase in
air-intlet temperature, will
increase linearly
decrease linearly
increase parabolically
decrease parabolically
first decrease linearly and
then increase parabolically.
ANSWER : : decrease linearly
12.In a typical medium speed, 4-stroke cycle diesel
engine
fuel injection starts at 10�
before to dead center and ends at 20� after tor dead center
fuel injection starts at top
dead center and ends at 20� after top dead center
fuel injection starts at just
before top dead center and ends just after top dead center
may start and end anywhere
none of the above.
ANSWER : : fuel injection starts at
10�before to dead center and
ends at 20�after tor dead
center
13.Compression loss in I.C engines occurs
duto
leaking piston rings
use of thick head gasket
clogged air-inlet slots
increase in clearance volume
caused b bearing-bushing wear
all of the above.
ANSWER : : all of the above.
14.In a typical medium speed 4-stroke cycle diesel
engine
compression starts at 35� after
bottom dead center and ends at top dead center
compression starts at bottom
dead center and ends at top dead center
compression starts at 10�
before bottom dead center and, ends just before top dead center
may start and end anywhere
none of the above.
ANSWER : : compression starts at
35�after bottom dead center and
ends at top dead center
15.If one cylinder of a diesel engine receives more fuel
than the others, then for that cylinder the
exhaust will be smoky
piston rings would stick into
piston grooves
exhaust temperature will be
high
engine starts overheating
scavenging occurs.
ANSWER : : scavenging occur
16.Diesel fuel, compared to petrol is
less difficult to ignite
just about the same difficult
to ignite
more difficult to ignite
highly ignitable
none of the above.
ANSWER : : more difficult to ignite
17.Which of the following medium is compressed in a
Diesel engine cylinder
air aione
air and fuel
air and lub oil
fuel alone
air, fuel and lub oil.
ANSWER : : air aione
18.For the same compression ratio
Otto cycle is more efficient
than the Diesel
Diesel cycle is more
efficient'than Otto
both Otto and Diesel cycles
are, equally efficient
compression ratio has nothing
to do with efficiency
which is more efficient would
depend on engine capacity.
ANSWER : : Otto cycle is more efficient than the
Diesel
19.When crude oil is heated, then which of the following
hydrocarbon is given off first.
kerosene
gasoline
paraffin
diesel
natural gas.
ANSWER : : natural gas.
20.Most high speed compression engines operate
on
Diesel cycle
Otto cycle
Dual combustion cycle
Special type of air cycle
Carnot cycle.
ANSWER : : Dual combustion cycle
21.As a result of detonation in an I.C. engine,
following parameter attains very high value
peak pressure
rate of rise of pressure
rate of rise of temperature
peak temperature
rate of rise of
horse-power.
ANSWER : : rate of rise of pressure
22.The inlet value of a four stroke cycle I.C engine
remains open for nearly
180�
125�
235�
200�
275�.
ANSWER : : 235�
23.The precess of breaking up or a liquid into fine
droplets by spraying is called
vaporisation
carburetion
ionisation
injection
atomisation.
ANSWER : : atomisation.
24.Which of the following statements is
cor�rect?
All the irreversible engines
have same efficiency
All the reversible engines have
same efficiency
Both Rankine and Caront cycles
have same efficiency between same tempera�ture limits
All reversible engines working
between same temperature limits have same-ef-ficiency
Between same temperature
limits, both petrol and diesel engines have same ef-ficiency.
ANSWER : : All reversible engines working between same
temperature limits have same-ef-ficiency
1.Pick up the wrong statement about
supercharging
supercharging reduces knocking
in diesel engines
there can be limited
supercharging in petrol engines because of detonation
supercharging at high altitudes
is essential
supercharging results in fuel
economy
supercharging is essential in
aircraft engines.
ANSWER : : supercharging results in fuel
economy
2.Engine pistons 'are usually made of aluminum alloy
because it
is lighter
wears less
absorbs shocks
is stronger
does not react with fuel and lub
oil.
ANSWER : : is lighter
3.The actual volume of fresh charge admitted in 4-stroke
petrol engine is
equal to stroke volume
equal to stroke volume and
clearance volume
less than stroke volume
more than stroke volume
more than cylinder volume.
ANSWER : : less than stroke volume
4.In diesel engine, the compression ratio in comparison
to expansion ratio is
same
less
more
variable
more/less depending on engine
capacity.
ANSWER : : more
5.Which of the following is false statement. Some of the
methods used to reduce diesel smoke are as follows
using additives in the fuel
engine derating i.e. reducing
the maxi-mum flow of fuel
increasing the compression
ratio
adherence to proper fuel
specification
avoidance of overloading.
ANSWER : : increasing the compression ratio
6.The term scavenging is generally associated
with
2-stroke cycle engines
4-stroke cycle engines
aeroplane engines
diesel engines
high efficiency engines.
ANSWER : : high efficiency engines.
7.The size of inlet valve of.an engine in comparison to
exhaust valve is
more
less
same
more/less depending on capacity
of engine
varies from design to
design.
ANSWER : : less
8.A diesel engine as compared to petrol engine (both
running ar rated load) is
more efficient
less efficient
equally efficient
unpredictable
other factors will decide
it.
ANSWER : : more efficient
9.Flash point of fuel oil is
minimum temperature to which1
oil is heated in order to give off inflammable vapours in
sufficient quantity to ignite momentarily when brought in contact
with a flame
temperature at which it
solidifies or congeals
temperature at which it catches
fire without external aid
indicated by 90% distillation
temperature, i.e. when 90% of sample oil has distilled off
none of the above.
ANSWER : : minimum temperature to which1 oil is heated
in order to give off inflammable vapours in sufficient quantity to
ignite momentarily when brought in contact with a
flame
10.In a typical medium speed 4 stroke cycle diesel
engine
exhaust valve opens at 35�
before bot-tom dead center and closes at 20� after top dead
center
exhaust valve opens at bottom
dead center and closes at top dead center
exhaust valve opens just after
bottom dead center and closes just before top dead center
may open and close anywhere
none of the above is true.
ANSWER : : exhaust valve opens at
35�before bot-tom dead center
and closes at 20�after top dead
center
11.Gaseous-fuel guarantees are based on
calorific value of oil
low heat value of oil
high heat value of oil
mean heat value of oil
all of the above.
ANSWER : : low heat value of oil
12.The cam shaft of a four stroke I.C. engine running at
1500 rmp will run at
1500 rpm
750 rpm
3000 rpm
any value independent of engine
speed
none of the above.
ANSWER : : 750 rpm
13.Polymerisation is a chemical process in which
molecules of a compound become
larger
slowed down
smaller
liquid
gaseous.
ANSWER : : larger
14.The fuel air ratio in a petrol engine fitted with
suction carburetor, operating with dirty air filter as compared to
clean filter will be
higher
lower
remain unaffected
unpredictable
none of the above.
ANSWER : : higher
15.Fuel consumption of diesel engines is not guaranteed
at one quarter load because at such low loads
the friction is high
the friction is
unpredictable
the small difference in cooling
water temperature or in internal friction has a disproportionate
effect
the engine is rarely
operated
none of the above.
ANSWER : : the small difference in cooling water
temperature or in internal friction has a disproportionate
effect
16.The operation of forcing additional air under
pressure in the engine cylinder is known as
scavenging
turbulence
supercharging
pre-ignition
dissociation and carburretion
of fuel.
ANSWER : : supercharging
17.Which of the following is false statement : Excess
quantities of sulphur in diesel fuel are Objectionable because it
may cause the following
piston ring and cylinder
wear
formation of hard coating on
piston skirts
oil sludge in the engine crank
case
detonation
forms corrosive acids.
ANSWER : : detonation
18.The reason for supercharging in any engine is
to
increase efficiency
increase power
reduce weight and bulk for a
given out-put
effect fuel economy
none of the above.
ANSWER : : reduce weight and bulk for a given
out-put
19.Supercharging is essential in
diesel engines
gas turbines
petrol engines
aircraft engines
marine engines.
ANSWER : : aircraft engines
20.In a cycle, the spark lasts roughly for
1 sec
0.1 sec
0.01 sec
0.001 sec
0.0001 sec.
ANSWER : : 0.001 sec
21.The minimum cranking speed in case of petrol engine
is about
half the operating speed
one-fourth of operating
speed
250-300 rpm
60-80 rpm
10-20 rpm
ANSWER : : 60-80 rpm
22.The magneto in an automobile is
basically
transformer
d.c. generator
capacitor
magnetic circuit
a.c. generator.
ANSWER : : d.c. generator
23.The specific fuel consumption of a petrol engine
compared to diesel engine of same H.P. is
same
more
less
less or more depending on
operating conditions
unpredictable.
ANSWER : : more
24.Most high speed compression engines operate
on
Otto cycle
Diesel cycle
Dual cycle
Carnot cycle
Two stroke cycle.
ANSWER : : Dual cycle
1.Air fuel ratio for idling speed of a petrol engine is
approximately
1 : 1
5 : 1
10:1
15 : 1
20 : 1.
ANSWER : : 10:1
2.In the opposed piston diesel engine, the combustion
chamber is located
above the piston (/;) below the
piston
between the pistons
any when
there is no such criterion.
opt 5
ANSWER : : between the pistons
3.In the crankcase method of scavenging, the air
pressure is produced by
supercharger
centrifugal pump
natural aspirator
movement of engine piston
reciprocating pump.
4.In loop scavenging, the top of the piston
is
flat
contoured
slanted
depressed
convex shaped.
ANSWER : : contoured
5.Scavenging is usually done to increase
thermal efficiency
speed
power output
fuel consumption
all of the above.
ANSWER : : power output
6.For maximum power generation, the air fuel ratio for a
petrol engine for vehicles, is of the order of
9 : 1
12 : 1
15 : 1
18 : 1
20: 1.
ANSWER : : 12 : 1
7.Air fuel ratio at which a petrol engine can not work
is
8 : 1
10 : 1
15 : 1
20 : 1 and less
will work at all ratios.
ANSWER : : 20 : 1 and less
8.Which of the following is the lightest and most
volatile liquid fuel
diesel
kerosene
fuel oil
gasoline
lub oil.
ANSWER : : gasoline
9.A stoichiometric air-fuel ratio is
chemically correct mixture
lean mixture
rich mixture for idling
rich mixture for over loads
the ratio used at full rated
parameters.
ANSWER : : chemically correct mixture
10.Pour point of fuel oil is the
minimum temperature to which
oil is heated in order to give off inflammable vapours in
sufficient quantity to ignite momentarily when brought in contact
with a flame
temperature at which it
solidifies or congeals
it catches fire without
external aid
indicated by 90% distillation
temperature i.e., when 90% of sample oil has distilled off
temperature at which it flows
easily.
ANSWER : : temperature at which it solidifies or
congeals
11.Installation of supercharger on a four-cycle diesel
engine can result in the following percentage increase in
power
upto 25%
upto 35%
upto 50%
upto 75%
upto 100%.
ANSWER : : upto 100%.
12.A hmh flame speed is obtained in diesel engine when
air fuel ratio is
uniform throughout the
mixture
chemically correct mixture
about 3-5% rich mixture
about 10% rich mixture
about 10% lean mixture.
ANSWER : : about 10% rich mixture
13.The following volume of air is required for consuming
1 liter of fuel by a four stroke engine
1 m3
5 m3
5-6 m3
9-10 m3
15-18 m3.
ANSWER : : 9-10 m3
14.The air-fuel ratio in petrol engines-is controlled
by
controlling valve
opening/closing
governing
injection
carburettion
scavenging and
supercharging.
ANSWER : : carburettion
15.A 5 BHP engine running at full load would consume
diesel of the order of
0.3 kg/hr
1 kg/hr
3 kg/hr
5 kg/hr
10 kg/hr.
ANSWER : : 1 kg/hr
16.The theoretically correct air fuel ratio for petrol
engine is of the order of
6 : 1
9 : 1
12 : 1
15 : 1
20 : 1.
ANSWER : : 15 : 1
17.In a naturally aspirated diesel engine, the air is
supplied by
a supercharger
a centrifugal blower
a vacuum chamber
an injection tube
forced chamber
ANSWER : : a vacuum chamber
18.For the same power developed in I.C. engines, the
cheaper system is
naturally aspirated
supercharged
centrifugal pump
turbo charger
none of the above.
ANSWER : : supercharged
19.Diesel engine can work on very lean air fuel ratio of
the order of 30 : 1. A petrol engine can also work on such a lean
ratio provided
it is properly designed
best quality fuel is used
can not work as it is
impossible
flywheel size is proper
engine cooling is stopped.
ANSWER : : can not work as it is impossible
20.A diesel engine has
1 valve
2 valves
3 valves
4 valves
no valve.
ANSWER : : 3 valves
21.The knock in diesel engine occurs due to
instantaneous and rapid burning
of the first part of the charge
instantaneous atuo iginition of
last part of charge
delayed burning of the first
part of the charge
reduction of delay period
all of the above.
ANSWER : : instantaneous and rapid burning of the first
part of the charge
22.Volatility of diesel fuel oil is
minimum temperature to which
oil is heated in order to give off inflam�mable vapours in
sufficient quantity to ignite momentarily when brought in contact
with a flame
temperature at which it
solidifies or congeals
it catches fire without
external aid
indicated by 90% distillation
temperature, i.e., when 90% of sample oil has distilled off
temperature at which it flows
easily.
ANSWER : : indicated by 90% distillation temperature,
i.e., when 90% of sample oil has distilled off
23.Which is more viscous lib oil
SEA 30
SAE 40
SAE 50
SAE 70
SAE 80.
ANSWER : : SAE 80.
1.
All the commercial liquid fuels are derived from natural
petroleum (or crude oil).
