Motor Engineering - MEO CLASS 4 MMD PAPER - Page 5 of 15

Presence of catalytic fines in fuel oil is significant to engineers on board because
1. Catalytic fines tend to impair proper operation of purifiers
2. Catalytic fines lead to abrasive wear in liners, piston rings and fuel injection equipment
3. Catalytic fines necessitate increase in injection temperature
4. Catalytic fines necessitate increase in storage temperature

ANS.: B

With reference to the data logger for a refrigerate sys. Which of the parameters should be noted?
1. Sea water temp, pressure
2. Condenser temp
3. Refrigerant leakage
4. Evaporator temp.

ANS.: A,B,D

Which of the following factors affect penetration of fuel droplets during injection?
1. Quality of atomization
2. Injection temperature
3. Scavenge air pressure
4. All of the above

ANS.: D

Lube oil pumps taking suction from the sump of most small marine engines are usually
1. of the diaphragm type
2. of the centrifugal type
3. positive displacement type
4. independently driven by electric motors

ANS.: C

Telescopic pipes to the piston of a large slow-speed main propulsion diesel engine are designed to prevent
1. excessive crankcase pressure
2. excessive lube oil temperature
3. contamination of the lube oil by water
4. contamination of the cooling water by lube oil

ANS.: C

Excessive axial thickness of a piston ring can lead to ________________
1. Scraping off of oil from liner surface
2. Increased wear
3. Twisting in the groove
4. Difficulty in formation of oil wedge

ANS.: D

Which of the following is an adhesive type wear of a cylinder liner?
1. Clover- leafing
2. Scoring
3. Scuffing
4. Ovality

ANS.: C

Cylinder heads of marine diesel engines are provided with _________ to relieve any excessive pressure within the combustion chamber
1. Safety valves
2. Indicator cocks
3. Relief valves
4. Bursting discs

ANS.: C

Working of a pulse pressure turbocharger depends upon the ___________ that can be safely created in the exhaust system.
1. Enthalpy drop
2. Pressure difference
3. Turbocharger rpm
4. Pressure pulses

ANS.: D

The maximum elongation of timing chains in service is limited to ___________ of original chain length.
1. 2%
2. 1%
3. 5%
4. 3%

ANS.: A

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 ____________
1. All tankers
2. Tankers above 10000 GT
3. Tankers above 100000 Dwt
4. All ships above

ANS.: B

Routine cleaning of air side of air cooler of main engine is done by:
1. Circulating fresh water
2. Circulating cold chemical solution
3. Circulating warm chemical solution
4. Circulating hot water

ANS.: C

What prevents rotation and fretting between a thin shell bearing and its housing?
1. Location tangs or pegs
2. The nip or crush of the bearing
3. A special kind of adhesive
4. Any of the above

ANS.: B

Microbial degradation of main engine sump oils can lead to:
1. Increased clogging of lube oil filters
2. Corrosive attack on journals and bearings
3. Formation of stable emulsions
4. All of the above

ANS.: D

In case of constant pressure turbo charging, the exhaust of the cylinders goes into :
1. Small diameter exhaust pipes with exhaust grouping
2. Exhaust compensators
3. Nozzles
4. Large diameter pipes

ANS.: B

Which of the following is a limiting factor in cylinder liner cooling?
1. Maximum combustion temperature
2. Minimum liner temperature
3. Exhaust temperature
4. Dew point for formation of sulphuric acid

ANS.: D

Which of the following is not a consequence of over lubrication of a cylinder liner?
1. Deposits in piston top land which can not only consume lube oil but always lead to increased abrasive wear .
2. Sticking and jamming of piston rings due to increased deposits.
3. Unburnt lube oil in scavenge spaces posing increased risk of scavenge fire .
4. Increased corrosive wear

ANS.: A

Variable geometry turbocharging is the preferred choice over conventional turbochargers because :
1. T/C efficiency is very high at high engine loads
2. T/C has good starting characteristics while efficiency at full loads is slightly compromised
3. T/C efficiency is optimized for different engine loads by changing nozzle ring geometry
4. T/C is much cheaper and simple to manufacture and is virtually maintenance free

ANS.: C

As a thumb rule, ovality in crankpins of medium speed engines should not exceed _______ of bearing clearance.
1. 10%
2. 15%
3. 25%
4. 30%

ANS.: C

In a naturally aspirated diesel engine, the volume of air intake is directly related to engine
1. compression ratio
2. valve size
3. fuel pressure
4. cylinder clearance volume

ANS.: B

Two important considerations for the proper lubrication of a diesel engine include, the delivery of the oil in sufficient amount, and the
1. cetane number
2. pour point
3. viscosity temperature
4. quality of the oil

ANS.: D

What is material of impeller of a T/C compressor ?
1. Stainless steel
2. Mild steel
3. Aluminium silicon
4. Bronze

ANS.: C

One of the major disadvantages of constant pressure turbocharging over pulse pressure turbocharging is :
1. Reduction in specific fuel consumption
2. Lengthening of effective stroke leading to greater expansion in engine
3. Poor turbocharging efficiency
4. Inability of the system to operate at low loads and slow response during acceleration

ANS.: D

Friction, engine wear, and oil consumption in a diesel engine are directly related to the
1. acidity of the oil
2. pour point of the oil
3. flash point of the oil
4. viscosity of the oil

ANS.: D

Improper maintenance of an automatic auxiliary boiler oil burner could result in
1. fuel pump failure
2. fan motor failure
3. increased feed water consumption
4. decreased boiler efficiency

ANS.: D

The effect of excessive tappet clearance is
1. Increased engine efficiency as expansion can take place for a longer duration and less energy wasted with the exhaust gases
2. Valve hammering, change in timing of exhaust with more side thurst causing greater wear between stem and bush
3. Loss in compression, poor combustion, improper mixing of fuel & air and gas leakage due to improper closing of valve
4. Turbocharger surging, loss of rotation of valve spindle and high exhaust temperatures

ANS.: B

The difference between rotocap and spinners for rotating exhaust valve spindle is that:
1. Rotocaps rotate the valves while closing, while spinners rotate them while opening
2. Rotocaps rotate the valves while opening, while spinners rotate them while closing
3. Rotocaps rotate the valves while opening, while spinners rotate the valve for the entire duration until valve is seated
4. Spinners rotate the valves while opening, while rotocaps rotate the valve for the entire duration until valve is seated

ANS.: C

Most fuel injection nozzles are opened by
1. fuel oil pressure
2. a cam operated follower
3. a spring-loaded pressure plate
4. timing gears keyed to the crankshaft

ANS.: A

Which of the following is a electro- hydraulic type steering gear
1. Rotary Vane type
2. Ram type
3. Both rotary vane type and ram type
4. None of the above

ANS.: C

Which of the following purposes is solved by a piston rod gland or stuffing box ?
1. To provide an air seal between scavenge space and crankcase
2. To prevent ingress of combustion products, unused cylinder lube oil, debris etc into the crankcase
3. To prevent carry over of sump oil into the crankcase
4. All of the above

ANS.: B

Which of the following is a feature of Sulzer TriboPack package?
1. Mid level liner insulation
2. Deep honing of liner
3. Pre- profiled and coated piston rings
4. All of the above

ANS.: D

In which of the following steering modes, rudder will be locked at a particular angle until next manual order?
1. Follow up
2. Auto pilot
3. Non Follow up
4. None of the above

ANS.: C

Failure of the burner flame in an automatic auxiliary boiler would probably be a result of uscg194
1. water in the fuel oil
2. broken high tension leads
3. incorrect electrode setting
4. full fuel pressure at the nozzle

ANS.: A

As per regulations, the torque capacity of a steering gear system should be such so as to be able to turn the rudder________________
1. 35 degrees one side to 35 degrees on the other side at maximum service speed
2. 35 degrees one side to 30 degrees on the other side at maximum service speed
3. 35 degrees one side to 35 degrees on the other side at normal service speed
4. 35 degrees one side to 30 degrees on the other side at normal service speed

ANS.: B

The output pressure of a diesel engine lube oil pump is regulated by a/an
1. relief valve
2. metering valve
3. variable speed pump drive
4. orifice in the lube oil header

ANS.: A

Most T/C have ——– flow type of Compressor and ——–flow type of Rotor
1. Centrifugal Radial , Impeller axial
2. Centrifugal axial, Impeller radial
3. Centrifugal mixed, Reaction Radial
4. Rotary axial, Reaction Radial

ANS.: A

Factors of lower limit of thrust by clearance
1. Adjustment of crankshaft
2. To allow thrust pads to tilt generated oil wedge
3. Proper lubrication

ANS.: B

Use of synthetic polymer treatment limited to low pr boiler, why?
1. does not help in prevention of scale formation
2. does not help in corrosion prevention
3. does not form phosphate to tackle caustic embrtllmnt
4. all of above