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Free download in PDF Marine Engineers Objective Type 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.
(21)
In modern marine 2-stroke diesel engines, ________________ is sometimes used as a coating on the underside of the exhaust valve disc, to reduce the rate of hot corrosion.
[A]
monel
[B]
chromium
[C]
inconel
[D]
cermet
(22)
Irregular circumferential wear of liner due to diminishing neutralizing capacity of cylinder oil away from lubricating holes is known as:
[A]
Micro seizure
[B]
Scuffing
[C]
Scoring
[D]
Clover leafing
(23)
Which of the following is a reasonable statement about water washing of turbine side of a T/C?
[A]
It leads to thermal shock and reduces the life of the T/C
[B]
It leads to thermal shock and not so effective as solid washing
[C]
If properly carried out keeping rpm, load, temperature limits & other factors into account; it is quite safe and more effective than solid washing
[D]
It should never be carried out as most of the engine manufacturers recommend against the same
Answer: If properly carried out keeping rpm, load, temperature limits & other factors into account; it is quite safe and more effective than solid washing
(24)
To check the setting of the over speed trip on a diesel powered generator, you would use a
[A]
tachometer
[B]
torsion meter
[C]
dynamometer
[D]
pony brake
(25)
Which of the following specifications/qualities of cylinder oils counter corrosive wear?
[A]
Viscosity
[B]
TBN
[C]
Detergency
[D]
Specific gravity
(26)
What is meant by elastohydrodynamic lubrication?
[A]
Formation of hydrodynamic film under high pressure with minor elastic deformation of mating surfaces, distributing load over a greater area
[B]
Addition of extreme pressure additive (EP) to the lubricant
[C]
Addition of Viscosity index improvement additive
[D]
Addition of elastomer based additives
Answer: Formation of hydrodynamic film under high pressure with minor elastic deformation of mating surfaces, distributing load over a greater area
(27)
In a bypass type filtering system for a medium or high speed diesel engine, the lube oil bypassing the filter
[A]
returns directly to the suction side of the pump
[B]
returns directly to the sump
[C]
flows to the engine bearings
[D]
flows through a second-stage strainer, reheated, and returns to the sump
Answer: flows to the engine bearings
(28)
Types of corrosion in fresh water of Diesel Engines
[A]
Stress
[B]
Hot corrosion
[C]
Bimetallic
[D]
Selective phase corrosion
Answer: Selective phase corrosion
(29)
Which of the following types of damages are metal seatings of a valve subject to? Choose the correct alternative.
[A]
Corrosion, Erosion, Abrasion, Deformation
[B]
Corrosion, Fatigue failure, brittle fracture, caustic cracking
[C]
Erosion, caustic cracking, brittle fracture, Clover leafing
[D]
None of the above
Answer: Corrosion, Erosion, Abrasion, Deformation
(30)
When A/E stand by F.O. heater to be used for main engine
[A]
Sudden opening F.O. inlet valve pressurized and damage the heater
[B]
F.O. in vapor lock inside heater allow steam
[C]
F.O. inlet valve causes pressure drop M/E F.O. pressure standby water is not pressurized may cause sudden change in engine /per load/rpm
[D]
Heater leaking
Answer: F.O. inlet valve causes pressure drop M/E F.O. pressure standby water is not pressurized may cause sudden change in engine /per load/rpm
31
Viscosity of fuel oil used for ME was 145cst, new fuel comes whose viscosity was more than earlier, what u should do
[A]
Increase temp setting
[B]
Change setting of viscotherm
[C]
Do nothing
[D]
Open steam valve manually more
32
Which of the following can be done to reduce the cold corrosion of Main Engine cylinder liners using high sulphur fuel oil
[A]
Increasing cylinder oil feed rate
[B]
Using high TBN cylinder oil
[C]
Increasing scavenge air temperature
[D]
Decreasing cylinder oil feed rate
Answer: Using high TBN cylinder oil
33
When main engine is running in emergency condition which of the alarms can't be bypassed
[A]
LO low pressure
[B]
Jacket water high temp
[C]
Piston cooling water high temp
[D]
All the above
34
The muffling of exhaust gas noise in 4 stroke auxiliary engines in achieved by
[A]
Allowing the gas to expand.
[B]
Change the direction of their flow.
[C]
Cool the gas with injected water.
[D]
Cool the gas with scavenges air.
35
To avoid the engine running too long on critical speed during start up it is necessary to
[A]
Start at speeds above critical speed.
[B]
Start at speeds just below critical speed and quickly move across the critical speed.
[C]
Start at maximum speed and quickly bring down to just above critical speed.
[D]
Eliminate totally the hazards of critical speed by ignoring it.
Answer: Start at speeds just below critical speed and quickly move across the critical speed.
36
When using low sulfur fuel oil for Emission Control Areas (ECA’S), ideally the TBN of the cylinder oil used should be
[A]
Lower than normal
[B]
Higher than normal
[C]
Same as normal
[D]
Same as normal if the feed is kept higher
Answer: Lower than normal
37
Which of the following functions is done by a cam operating an exhaust valve?
[A]
It governs the timing of opening and closing of the valve.
[B]
It governs the speed at which the valve operates
[C]
It governs the amount of opening of the valve
[D]
All of the above
38
In the latest concept of Variable Geometry Turbocharging, _______angle can be varied to match the turbocharger at varying engine loads
[A]
Compressor vane
[B]
Turbine blade
[C]
Nozzle ring blade
[D]
Diffuser ring blade
Answer: Nozzle ring blade
39
Directional intake ports in diesel engines are used to
[A]
reduce air charge turbulence
[B]
induce air swirl
[C]
deflect hot combustion gas away from the valves
[D]
oppose the effects of piston induced squish
40
Why does a chain stretch in service?
[A]
Due to plastic elongation
[B]
Due to high temperature expansion
[C]
Due to wear on rollers and bushes
[D]
Due to the phenomenon of creep
Answer: Due to wear on rollers and bushes
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