Practice Internal Combustion Engines (I.C. Engines) Multiple Choice Questions Quiz-6

Q.1

The brake power is the power available

In the engine cylinder
At the crank shaft
At the crank pin
None of these

Q.2

In a typical medium speed, 4-stroke cycle diesel engine

Fuel injection starts at 10° before top dead center and ends at 20° after top 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

Q.3

In a coil ignition system of petrol engines, a condenser is connected across the contact breaker in order to

Prevent sparking across the gap between the points
Cause more rapid break of the primary current, giving a higher voltage in the secondary circuit
Both (A) and (B)
None of the above

Q.4

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

Q.5

In a four stroke cycle, the minimum temperature inside the engine cylinder occurs at the

Beginning of suction stroke
End of suction stroke
Beginning of exhaust stroke
End of exhaust stroke

Q.6

A diesel engine has

1 valve
2 valves
3 valves
4 valves

Q.7

The calorific value of gaseous fuels is expressed in terms of

kcal
kcal/kg
kcal/m²
kcal/m³

Q.8

A diesel engine has compression ratio from

6 to 10
10 to 15
15 to 25
25 to 40

Q.9

Which one of the following engines will have heavier flywheel than the remaining ones?

30 kW four-stroke petrol engine running at 1500 r.p.m.
30 kW two-stroke petrol engine running at 1500 r.p.m.
30 kW two-stroke diesel engine running at 750 r.p.m.
30 kW four-stroke diesel engine running at 750 r.p.m.

Q.10

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

Q.11

The self ignition temperature of petrol is _________ as compared to diesel oil.

Same
Lower
Higher
None of these

Q.12

Which of the following statement is correct?

Compression ratio for petrol engines varies from 6 to 10
Higher compression ratio in diesel engines results in higher pressures
Petrol engines work on Otto cycle
All of the above

Q.13

The pressure inside the cylinder is _________ the atmospheric pressure during the exhaust stroke.

Equal to
Below
Above
None of these

Q.14

A petrol engine has compression ratio from

6 to 10
10 to 15
15 to 25
25 to 40

Q.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

Q.16

The exhaust valve in a four stroke cycle petrol engine

Opens at 50° before bottom dead center and closes at 15° after top dead center
Opens at bottom dead center and closes at top dead center
Opens at 50° after bottom dead center and closes at 15° before top dead center
May open and close anywhere

Q.17

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

Q.18

The air standard efficiency of an I.C. engine depends on

Fuel used
Speed of engine
Compression ratio
None of these

Q.19

Pick up the false statement

Thermal efficiency of diesel engine is about 34%
Theoretically correct mixture of air and petrol is approximately 15:1
High speed compression engines operate on dual combustion cycle
S.I. engines are quality governed engines

Q.20

The two reference fuels used for cetane rating are

Cetane and iso-octane
Cetane and alpha-methyl naphthalene
Cetane and normal heptane
Cetane and tetra ethyl lead

Q.21

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-stroke engine is more due to positive scavenging
Petrol engines occupy more space than diesel engines for same power output

Q.22

The ratio of the brake power to the indicated power is called

Mechanical efficiency
Overall efficiency
Indicated thermal efficiency
Volumetric efficiency

Q.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

Q.24

For the same power developed in I.C. engines, the cheaper system is

Naturally aspirated
Supercharged
Centrifugal pump
Turbo charger

Q.25

As compared to air standard cycle, in actual working, the effect of variation in specific heats is to

Increase maximum pressure and maximum temperature
Reduce maximum pressure and maximum temperature
Increase maximum pressure and decrease maximum temperature
Decrease maximum pressure and increase maximum temperature

Q.26

The expansion of fuel in a four stroke cycle diesel engine

Starts at 15° before top dead center and ends at 30° after top dead center
Starts at top dead center and ends at 30° after top dead center
Starts at 15° after top dead center and ends at 30° before bottom dead center
May start and end anywhere

Q.27

The fuel valve in a four stroke cycle diesel engine

Opens at 15° after top dead center and closes at 20° before bottom dead center
Opens at 15° before top dead center and closes at 20° after top dead center
Opens at top dead center and closes at bottom dead center
May open and close anywhere

Q.28

Which of the following statement is wrong?

In compression ignition engines, detonation occurs near the beginning of combustion.
Since the fuel, in compression ignition engines, is injected at the end of compression stroke, therefore, there will be no pre-ignition.
To eliminate knock in compression ignition engines, we want to achieve auto-ignition not early and desire a long delay period.
In compression ignition engines, because of heterogeneous mixture, the rate of pressure rise is comparatively lower.

Q.29

Which of the following statement is wrong?

A four stroke cycle engine develops twice the power as that of a two stroke cycle engine
For the same power developed, a four stroke cycle engine is lighter, less bulky and occupies less floor area
The petrol engines are costly than diesel engines
All of the above

Q.30

The magneto in an automobile is basically

Transformer
D.C. generator
Capacitor
Magnetic circuit

The brake power is the power available

In a typical medium speed, 4-stroke cycle diesel engine

In a coil ignition system of petrol engines, a condenser is connected across the contact breaker in order to

The fuel in diesel engine is normally injected at pressure of

In a four stroke cycle, the minimum temperature inside the engine cylinder occurs at the

A diesel engine has

The calorific value of gaseous fuels is expressed in terms of

A diesel engine has compression ratio from

Which one of the following engines will have heavier flywheel than the remaining ones?

In a typical medium speed 4-stroke cycle diesel engine

The self ignition temperature of petrol is _________ as compared to diesel oil.

Which of the following statement is correct?

The pressure inside the cylinder is _________ the atmospheric pressure during the exhaust stroke.

A petrol engine has compression ratio from

In a typical medium speed 4-stroke cycle diesel engine the inlet valve

The exhaust valve in a four stroke cycle petrol engine

For the same compression ratio

The air standard efficiency of an I.C. engine depends on

Pick up the false statement

The two reference fuels used for cetane rating are

Pick up the wrong statement

The ratio of the brake power to the indicated power is called

The specific fuel consumption of a petrol engine compared to diesel engine of same H.P. is

For the same power developed in I.C. engines, the cheaper system is

As compared to air standard cycle, in actual working, the effect of variation in specific heats is to

The expansion of fuel in a four stroke cycle diesel engine

The fuel valve in a four stroke cycle diesel engine

Which of the following statement is wrong?

Which of the following statement is wrong?

The magneto in an automobile is basically

0 h : 0 m : 1 s

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