MEK (Motor) asked Questions Part 1



1.The scavenge ports o f a uniflow scavenged 2-stroke engme cylinder liner are machined at an obli
angle to the axis o f the cylinder, why ?
A. To prevent exhamt gases from coming out o f scavenge ports
B. To allow rotary motion to scavenge air to reduce exhaust gas temperature for reduced NOx emission
C. To allow rotary motion to scavenge air for better scavenging and better air-fuel mixing
D. To allow rotary motion to scavenge air for better cylinder oil distribution on the liner walls and better
turbocharger performance


2. Which standards govern the specifications for supply of Residual Marine Fuels and Distillate Marine Fuels onboard merchant ships?
A. ISO 3012:1999
B. ISO 3648:1996
C. ISO 8216-1:2010
D. ISO 8217:2010
3. Crank web deflection readings will give a positive indication of
A. worn main bearing journals
B. torsional stress deformation
C. slack thrust bearings
D. bearing shells shim dimensions
 
4. use of synthetic polymer treatment limited to low pr boiler, why?
a. does not help in prevention of scale formation
b. does not help in corrosion prevention
c. does not form phosphate to tackle caustic embritlment
d. all of above
5. The output pressure of a diesel engine lube oil pump is regulated by a/an
A. relief valve
B. metering valve
C. variable speed pump drive
D. orifice in the lube oil header
6. Most T/C have -------- flow type of Compressor and --------flow type of Rotor
a. Centrifugal Radial , Impeller axial
b. Centrifugal axial, Impeller radial
c. Centrifugal mixed, Reaction Radial
d. Rotary axial, Reaction Radial
7. Factors of lower limit of thrust by clearance
a. Adjustment of crankshaft
b. To allow thrust pads to tilt generated oil wedge
c. Proper lubrication
8. Two important considerations for the proper lubrication of a diesel engine include, the delivery of the oil in sufficient amount, and the
A. cetane number
B. pour point
C. viscosity temperature
D. quality of the oil
9. What is material of impeller of a T/C compressor ?
A. Stainless steel
B. Mild steel
C. Aluminium silicon
D. Bronze
10. One of the major disadvantages of constant pressure turbocharging over pulse pressure turbocharging is :
A. Reduction in specific fuel consumption
B. Lengthening of effective stroke leading to greater expansion in engine
C. Poor turbocharging efficiency
D. Inability of the system to operate at low loads and slow response during acceleration
11. Friction, engine wear, and oil consumption in a diesel engine are directly related to the
A. acidity of the oil
B. pour point of the oil
C. flash point of the oil
D. viscosity of the oil
12. Improper maintenance of an automatic auxiliary boiler oil burner could result in
A. fuel pump failure
B. fan motor failure
C. increased feedwater consumption
D. decreased boiler efficiency
13. The effect of excessive tappet clearance is:
A. Increased engine efficiency as expansion can take place for a longer duration and less energy wasted with the exhaust gases
B. Valve hammering, change in timing of exhaust with more side thurst causing greater wear between stem and bush
C. Loss in compression, poor combustion, improper mixing of fuel & air and gas leakage due to improper closing of valve
D. Turbocharger surging, loss of rotation of valve spindle and high exhaust temperatures
14. The difference between rotocap and spinners for rotating exhaust valve spindle is that:
A. Rotocaps rotate the valves while closing, while spinners rotate them while opening
B. Rotocaps rotate the valves while opening, while spinners rotate them while closing
C. Rotocaps rotate the valves while opening, while spinners rotate the valve for the entire duration until valve is seated
D. Spinners rotate the valves while opening, while rotocaps rotate the valve for the entire duration until valve is seated
15. Most fuel injection nozzles are opened by
A. fuel oil pressure
B. a cam operated follower
C. a spring-loaded pressure plate
D. timing gears keyed to the crankshaft
16. Which of the following is a electro- hydraulic type steering gear
A. Rotary Vane type
B. Ram type
C. Both rotary vane type and ram type
D. None of the above
17. Which of the following purposes is solved by a piston rod gland or stuffing box ?
A. To provide an air seal between scavenge space and crankcase
B. To prevent ingress of combustion products, unused cylinder lube oil, debris etc into the crankcase
C. To prevent carry over of sump oil into the crankcase
D. All of the above
18. Which of the following is a feature of Sulzer TriboPack package?
A. Mid level liner insulation
B. Deep honing of liner
C. Pre- profiled and coated piston rings
D. All of the above
19. In which of the following steering modes, rudder will be locked at a particular angle until next manual order?
A. Follow up
B. Auto pilot
C. Non Follow up
D. None of the above
20. Failure of the burner flame in an automatic auxiliary boiler would probably be a result of
A. water in the fuel oil
B. broken high tension leads
C. incorrect electrode setting
D. full fuel pressure at the nozzle
21. As per regulations, the torque capacity of a steering gear system should be such so as to be able to turn the rudder__________________________
A. 35 degrees one side to 35 degrees on the other side at maximum service speed
B. 35 degrees one side to 30 degrees on the other side at maximum service speed
C. 35 degrees one side to 35 degrees on the other side at normal service speed
D. 35 degrees one side to 30 degrees on the other side at normal service speed
22. What prevents rotation and fretting between a thin shell bearing and its housing?
A. Location tangs or pegs
B. The nip or crush of the bearing
C. A special kind of adhesive
D. Any of the above
23. Microbial degradation of main engine sump oils can lead to:
A. Increased clogging of lube oil filters
B. Corrosive attack on journals and bearings
C. Formation of stable emulsions
D. All of the above.
24. In case of constant pressure turbo charging, the exhaust of the cylinders goes into :
A. Small diameter exhaust pipes with exhaust grouping
B. Exhaust compensators
C. Nozzles
D. Large diameter pipes
25. Which of the following is a limiting factor in cylinder liner cooling?
A. Maximum combustion temperature
B. Minimum liner temperature
C. Exhaust temperature
D. Dew point for formation of sulfuric acid
26. Which of the following is not a consequence of over lubrication of a cylinder liner?
A. Deposits in piston top land which can not only consume lube oil but always lead to increased abrasive wear
.B. Sticking and jamming of piston rings due to increased deposits.
C. Unburnt lube oil in scavenge spaces posing increased risk of scavenge fire .
D. Increased corrosive wear
27. Variable geometry turbocharging is the preferred choice over conventional turbochargers because :
A. T/C efficiency is very high at high engine loads
B. T/C has good starting characteristics while efficiency at full loads is slightly compromised
C. T/C efficiency is optimized for different engine loads by changing nozzle ring geometry
D. T/C is much cheaper and simple to manufacture and is virtually maintenance free
28. As a thumb rule, ovality in crankpins of medium speed engines should not exceed _____________ of bearing clearance.
A. 10%
B. 15%
C. 25%
D. 30%
29. 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
30. Lube oil pumps taking suction from the sump of most small marine engines are usually
A. of the diaphragm type
B. of the centrifugal type
C. positive displacement type
D. independently driven by electric motors
31. Telescopic pipes to the piston of a large slow-speed main propulsion diesel engine are designed to prevent
A. excessive crankcase pressure
B. excessive lube oil temperature
C. contamination of the lube oil by water
D. contamination of the cooling water by lube oil
32. Excessive axial thickness of a piston ring can lead to ____________________
A. Scraping off of oil from liner surface
B. Increased wear
C. Twisting in the groove
D. Difficulty in formation of oil wedge
33. Which of the following is an ???adhesive??? type wear of a cylinder liner?
A. Clover- leafing
B. Scoring
C. Scuffing
D. Ovality
34. Cylinder heads of marine diesel engines are provided with _________ to relieve any excessive pressure within the combustion chamber
A. Safety valves
B. Indicator cocks
C. Relief valves
D. Bursting discs
35. Working of a pulse pressure turbocharger depends upon the ___________ that can be safely created in the exhaust system.
A. Enthalpy drop
B. Pressure difference
C. Turbocharger rpm
D. Pressure pulses
36. The maximum elongation of timing chains in service is limited to ___________ of original chain length.
A. 2%
B. 1%
C. 5%
D. 3%
37. Duplication of power units, fittings and pipings where each unit is capable of providing 100% steering power, and automatic isolation of one unit in the event of a leakage(single failure) in that unit would constitute 100% redundancy for the steering gear system. Such system is mandatory on ____________
A. All tankers
B. Tankers above 10000 GT
C. Tankers above 100000 Dwt
D. All ships above
38. Routine cleaning of air side of air cooler of main engine is done by:
A. Circulating fresh water
B. Circulating cold chemical solution
C. Circulating warm chemical solution
D. Circulating hot water
 

39. 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.
40. The arrangement used to protect overheating of the superheaters under fluctuating loads is called
A. De-superheater
B. Attemperator
C. Steam dumping valve
D. Feed heater
41. 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
42. In a 2-stroke engine a ________________ separates the under piston space from the crankcase.
A. A-frame
B. Crosshead
C. Diaphragm
D. Scavenge space
43. Fusible plugs are installed in fire-tube boilers to
A. provide a means of draining the boiler
B. warn the engineer of low water level
C. cool the crown sheet at high firing rates
D. open the burners' electrical firing circuits
44. 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
45. In a coil-type auxiliary water-tube circulation boiler
A. unevaporated feedwater collects in the bottom of the flash chamber
B. all generated steam is recirculated through heating coils in the boiler
C. heated water flashes to steam in the boiler heating coils
D. response to steam demand is slower than in a fire-tube boiler
46. 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
47. As per regulations, within how many hours before each departure, satisfactory working of the steering gear must be checked?
A. 2
B. 12
C. 24
D. None of the above
48. Modern 4-stroke medium speed, marine diesel engine exhaust valve spindles are rotated by providing
A. Nozzle rings
B. Tappet clearance
C. Spinners or vanes
D. Rotocaps
49. The purpose of economizer is to:
A. Decrease the capacity and size of the auxiliary boiler
B. Cooling down the exhaust gases in order to reduce NOx emission
C. Allowing Sox to react at low temperatures with water to form acids thus reducing Sox emission
D. Increasing the overall efficiency of the main propulsion plant
50. Microbiological growths in marine fuel are a common occurrence that can be
A. extremely detrimental to equipment and operating processes
B. prevented by maintaining proper storage temperatures
C. removed from emulsified fuel oil during the centrifuging processes
D. All of the above are correct.




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