Chapter: Fuels and its Supply System SI and CI engine
101.
The choke is closed when the engine is
A.
accelerating
B.
hot
C.
cold
D.
idling
Answer»
C. cold
102.
Lean air mixture is required during
A.
idling
B.
starting
C.
accelerating
D.
cruising
Answer»
D. cruising
103.
The limits of air-fuel for SI engine are
A.
8/1 to 18/1
B.
8/1 to 50/1
C.
25/1 to 50/1
D.
50/1 to 100/1
Answer»
A. 8/1 to 18/1
104.
For maximum thermal efficiency, the fuel-air mixture in SI engines should be
A.
lean
B.
rich
C.
stoichiometric
D.
may be rich or lean
Answer»
A. lean
105.
During starting petrol engines require
A.
stoichiometric mixture
B.
lean mixture
C.
rich mixture
D.
any air-fuel ratio is alright
Answer»
C. rich mixture
106.
Economizer is used to provide enriched mixture during
A.
Starling
B.
idling
C.
cruising
D.
full throttle operation
Answer»
D. full throttle operation
107.
When the throttle is suddenly opened, the mixture of the simple carburetor tends to
become
A.
rich
B.
lean
C.
stoichiometric
D.
not affected
Answer»
B. lean
108.
Precise petrol injection system is
A.
direct injection
B.
sequential injection
C.
throttle body injection
D.
port injection
Answer»
C. throttle body injection
109.
The choke in an automobile meant for supplying
A.
lean mixture
B.
rich mixture
C.
stoichiometric mixture
D.
weak mixture
Answer»
B. rich mixture
110.
Modern carburetors provide the correct quality of air-fuel mixture during
A.
starting
B.
idling
C.
cruising
D.
all conditions
Answer»
D. all conditions
111.
A simple carburetor supplies rich mixture during
A.
starting
B.
idling
C.
cruising
D.
accelerating
Answer»
D. accelerating
112.
Fuel injector is used for
A.
gas engines
B.
CI engines
C.
SI engines
D.
none of the above
Answer»
B. CI engines
113.
Advantage of air injection system is
A.
cheaper fuels can be used
B.
mep is high
C.
fine atomization and distribution of the fuel
D.
all of the above
Answer»
D. all of the above
114.
Commonly used injection system in automobiles is
A.
air injection
B.
solid injection
C.
combination of (a) and (b)
D.
none of the above
Answer»
B. solid injection
115.
Fuel injection pressure in solid injection system is around
A.
<10 bar
B.
10-20 bar
C.
30-50 bar
D.
200-250 bar
Answer»
D. 200-250 bar
116.
Fuel filters do not use generally
A.
oil
B.
paper
C.
cloth
D.
felt
Answer»
B. paper
117.
Fuel is injected in a four-stroke CI engine
A.
at the end of suction stroke
B.
at the end of expansion stroke
C.
at the end of compression stroke
D.
at the end of exhaust stroke
Answer»
C. at the end of compression stroke
118.
Injection system in which the pump and the injector nozzle is combined in one housing is known as
A.
common rail system
B.
distributor system
C.
unit injector system
D.
individual pump and nozzle system
Answer»
C. unit injector system
119.
Main advantage of pintaux nozzle is
A.
better cold starting performance
B.
ability to distribute the fuel
C.
good penetration
D.
good atomization
Answer»
A. better cold starting performance
120.
the most accurate gasoline injection system is
A.
direct injection
B.
port injection
C.
throttle body injection
D.
manifold injection
Answer»
B. port injection
121.
Advantage of fuel injection in SI engine is
A.
low initial cost
B.
low maintenance requirements
C.
increased volumetric efficiency
D.
none of the above
Answer»
C. increased volumetric efficiency
122.
‘MPFI’ stands for
A.
Multi point fuel injection
B.
Multi port fuel injection
C.
Manifold point fuel injection
D.
Manifold port fuel injection
Answer»
A. Multi point fuel injection
123.
In carburetor, Choke is incorporated
A.
Before the venturi
B.
After the venturi
C.
In the venturi
D.
Any of the above
Answer»
A. Before the venturi
124.
The following factors affect the process of carburetion
A.
Engine speed
B.
The temperature of incoming air
C.
The volatility of fuel
D.
All of the above
Answer»
D. All of the above
125.
In MPFI _____ is used to spray fuel into engine.
A.
Engine vacuum
B.
Suction pressure of engine
C.
Electric pump
D.
None of the above
Answer»
B. Suction pressure of engine
126.
L-MPFI system uses
A.
port injection
B.
direct injection
C.
manifold injection
D.
throttle body injection
Answer»
A. port injection
127.
D-MPFI system uses
A.
port injection
B.
manifold injection
C.
direct injection
D.
throttle body injection
Answer»
B. manifold injection
128.
Common rail injection system uses injection pressures of the order
A.
100-200 bar
B.
200-400 bar
C.
400-600 bar
D.
1500 bar
Answer»
D. 1500 bar
129.
Continuous injection system usually has
A.
plunger pump
B.
rotary pump
C.
gear pump
D.
vane pump
Answer»
B. rotary pump
130.
The cold start injector
A.
maintain stoichiometric air-fuel ratio
B.
provides lean air-fuel ratio
C.
gives rich air-fuel ratio
D.
is not used for any of the above functions
Answer»
C. gives rich air-fuel ratio
131.
ECU is an electronic injection system used for
A.
calculating the appropriate injection timing
B.
meeting only certain operating conditions
C.
closing the injection valve only
D.
none of the above
Answer»
A. calculating the appropriate injection timing
132.
With EFI (ELECTRONIC FUEL INJECTION) of diesel engines
A.
sharp start and stop is not possible
B.
very high injection pressure can be obtained
C.
sudden cylinder cut-off is impossible
D.
diagnostic properties are poor
Answer»
B. very high injection pressure can be obtained
133.
EFI system can achieve
A.
proper injection timing
B.
proper injection quantity
C.
proper injection pressure
D.
all of the above
Answer»
D. all of the above
134.
The first vehicle in India equipped with MPFI system in Indian automobile industry
A.
Tata Indica
B.
Daewoo Matiz
C.
Maruti Alto
D.
Chevrolet spark
Answer»
B. Daewoo Matiz
135.
The fuel in diesel engine is normally injected at pressure of
A.
5-10 kg/cm2
B.
20-25 kg/cm2
C.
60-80 kg/cm2
D.
90-130 kg/cm2
Answer»
D. 90-130 kg/cm2
136.
The specific fuel consumption per BHP hour for diesel engine is approximately
A.
0.15 kg
B.
0.2 kg
C.
0.25 kg
D.
0.3 kg
Answer»
B. 0.2 kg
137.
The specific fuel consumption per BH hour for a petrol engine is approximately
A.
0.15 kg
B.
0.2 kg
C.
0.25 kg
D.
0.3kg
Answer»
C. 0.25 kg
138.
The air-fuel ratio of the petrol engine is controlled by
A.
fuel pump
B.
governor
C.
injector
D.
carburettor
Answer»
D. carburettor
139.
Pour point of fuel oil is the
A.
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
B.
temperature at which it solidifies or congeals
C.
it catches fire without external aid
D.
indicated by 90% distillation temperature i.e., when 90% of sample oil has distilled off
Answer»
B. temperature at which it solidifies or congeals
140.
A 5 BHP engine running at full load would consume diesel of the order of
A.
0.3 kg/hr
B.
1 kg/hr
C.
3 kg/hr
D.
5 kg/hr
Answer»
B. 1 kg/hr
Chapter: Ignition and Governing System
141.
The secondary winding of ignition coil consists of
A.
few turns of fine wire
B.
few turns of thick wire
C.
many turns of fine wire
D.
many turns of thick wire
Answer»
C. many turns of fine wire
142.
Dwell is the time
A.
for which the points remain closed
B.
for which the points remain open
C.
time during which inlet and exhaust valves are open
D.
none of the above
Answer»
A. for which the points remain closed
143.
Dwell period
A.
is directly proportional to engine speed
B.
is inversely proportional to engine speed
C.
does not depend on engine speed
D.
none of the above
Answer»
B. is inversely proportional to engine speed
144.
If the contact breaker gap is small, it results in
A.
advanced timing
B.
increased dwell
C.
rapid burning of the pointer gaps
D.
none of the above
Answer»
C. rapid burning of the pointer gaps
145.
For a four cylinder engine operating at N rpm, the contact breaker must make and break the
circuit
A.
N times
B.
2N times
C.
N/2 times
D.
none of the above
Answer»
B. 2N times
146.
Contact breaker should be set
A.
just before starting the engine
B.
before adjustment of dwell angle
C.
after adjustment of dwell angle
D.
before setting spark plug gap
Answer»
C. after adjustment of dwell angle
147.
Dwell meter is used for
A.
setting spark plug gap
B.
contact breaker gap
C.
setting the ignition advance
D.
setting
Answer»
B. contact breaker gap
148.
For a four cylinder vertical engine, the commonly used firing order is
A.
1-2-3-4
B.
3-4-1-2
C.
1-3-4-2
D.
4-3-2-1
Answer»
C. 1-3-4-2
149.
For engine operating with rich mixtures the optimum spark timing
A.
must be advanced
B.
must be retarded
C.
must be at TDC
D.
none of the above
Answer»
A. must be advanced
150.
For peak lead operation, the spark advance
A.
must be decreased
B.
must be increased
C.
need not be altered
D.
none of the above
Answer»
A. must be decreased
151.
Ignition timing is adjusted by
A.
tachometer
B.
stroboscopic light
C.
stop watch
D.
accurate clock
Answer»
B. stroboscopic light
152.
Vacuum advance mechanism shifts the ignition point under
A.
no load operation
B.
full load operation
C.
part load operation
D.
under sudden acceleration
Answer»
C. part load operation
153.
Which of the following statement is wrong?
A.
retarded timing causes exhaust gas temperature to be higher
