Questions
Download PDF
Free download in PDF Marine Engineers Short Questions and Answers for competitive exams. These short objective type questions with answers are very important for Board exams as well as competitive exams. These short solved questions or quizzes are provided by Gkseries.
41
Which of the following methods is normally used to lubricate bearings in a small highspeed diesel engine?
A
Splash lubrication
B
Pressure lubrication
C
Sight feed lubricators
D
Mechanical lubricators
View Answer
Answer: Pressure lubrication
42
What is the purpose of the inlet grid provided within the exhaust gas casing in the gas flow path, prior entry to turbocharger?
A
To filter out any unburned carbon
B
To absorb and dampen the pressure fluctuation
C
To reduce noise in the constant pressure exhaust piping
D
To prevent any broken piston rings finding their way to turbine
View Answer
Answer: To filter out any unburned carbon
Advertisement
43
The main function of tie rods in the construction of large, low speed diesel engines is to
A
stiffen the bedplate in way of the main bearings to increase the engine's longitudinal strength
B
accept most of the tensile loading that results from the firing forces developed during operation
C
mount the engine frame securely to the hull to prevent shaft coupling misalignment
D
connect the crosshead solidly to the piston rod
View Answer
Answer: accept most of the tensile loading that results from the firing forces developed during operation
44
The fall in speed that occurs in a diesel engine equipped with governor, on increase of load is called:
A
Offset
B
Speed drop
C
Speed droop
D
Speed offset
View Answer
45
Which of the following factors governs the lower limit of thrust bearing clearance?
A
To allow some oil leakage to prevent overheating
B
Reduction of oil viscosity
C
Alignment of crankshaft
D
To allow the thrust pads to tilt and generate the oil wedge
View Answer
Answer: To allow the thrust pads to tilt and generate the oil wedge
46
Which of the following can result in cracking of piston crown?
A
Deposits in cooling spaces
B
Impingement of fuel due to faulty injection
C
Insufficient piston cooling oil flow
D
All of the above
View Answer
47
What does the NLGI number of grease indicate?
A
The oxidation resistance of the grease
B
The consistency of the grease i.e how fluid or non fluid
C
Demulsibility of the grease
D
The shelf life of the grease
View Answer
Answer: The consistency of the grease i.e how fluid or non fluid
48
Which of the following layers of a thin shell bearing gives it its fatigue strength?
A
The overlay
B
The interlay
C
The backing
D
The barrier layer
View Answer
49
Which of the bearings listed is most widely used for main and connecting rod bearings of modern diesel engines?
A
Steel-lined
B
Poured babbitt, self-aligning
C
Split roller
D
Precision insert
View Answer
50
Which of the following statements is false?
A
The fuel oil sulfur level is one of the important criteria for choice of TBN level of cylinder oil.
B
The use of anti-polishing rings or flame rings increases the consumption of cylinder oil
C
Excessive cylinder oil feed can lead to harmful deposits in piston top land area
D
None of the above
View Answer
Answer: The use of anti-polishing rings or flame rings increases the consumption of cylinder oil
51
Prompt correction of speed of diesel engines driving alternators, without having massive fluctuations is ensured by incorporating:
A
Load limiting devices
B
Load sharing devices
C
Load sensing devices
D
Load shedding devices
View Answer
Answer: Load sensing devices
52
In a uniflow scavenged marine 2-stroke diesel engine, the scavenge ports in a cylinder liner are machined
A
Only for a part of the circumference, at an angle almost tangential to the circumference of the liner
B
All around the circumference at right angles to the circumference of the liner
C
only for a part of the circumference, at right angles to the circumference of the liner
D
All around the circumference at an angle almost tangential to the circumference of the liner
View Answer
Answer: All around the circumference at an angle almost tangential to the circumference of the liner
53
If the tappet clearance between the rocker arm tappet and exhaust valve stem is excessive then:
A
The valve will open early and close later
B
The valve will open later and close early
C
The valve will open and close later
D
The valve will open and close early
View Answer
Answer: The valve will open later and close early
54
Which of the following conditions can lead to reduced power developed by a main engine?
A
High scavenge air temperature
B
Choked air suction filter of a turbocharger
C
Blow past in one or more units
D
All of the above
View Answer
55
Which of the following types of diagrams would give an indication of effectiveness of exhaust and scavenge processes?
A
Power card
B
Draw card
C
Light spring diagram
D
All of the above
View Answer
Answer: Light spring diagram
56
In a naturally aspirated diesel engine, the volume of air intake is directly related to engine
A
compression ratio
B
valve size
C
fuel pressure
D
cylinder clearance volume
View Answer
57
Piston rod stuffing box scraper rings butt clearances should:
A
Not to be allowed to fall below 50% of original clearance
B
Not to be allowed to increase above 50% of original clearance
C
Not to be allowed to fall below manufacturer recommended value
D
Not to be allowed to increase above manufacturer recommended value
View Answer
Answer: Not to be allowed to fall below manufacturer recommended value
58
In a 2-stroke engine a _________ separates the under piston space from the crankcase.
A
A-frame
B
Crosshead
C
Diaphragm
D
Scavenge space
View Answer
59
Which of the following gauges are generally used to evaluate main bearing clearances?
A
Poker gauge
B
Feeler gauge
C
Telescopic feeler gauge
D
Dial gauge
View Answer
Answer: Telescopic feeler gauge
60
For a continuous operation diesel engine, a duplex filter unit would be the best arrangement because
A
changing filter elements would not interrupt engine operation
B
filtering occurs twice in each pass of oil through the system
C
clogging will not occur
D
dropping pressure is half of that through a single filter unit
View Answer
Answer: changing filter elements would not interrupt engine operation
