Ajit Vadakayil Questions

REFRIGERATION

1)During standstill liquid may condense in the crankcase or oil separator. Why is it important to heat up the oil before start?

a)The compressor will run better.

b)It should never be done.

c)To avoid the compressor-oil disappearing from the crankcase during starting.

d)Compressor oil regulating system will operate better.

2) Personnel working with refrigeration systems, and subject to the exposure of refrigerants should wear

a)face shield

b)a respirator

c)rubber gloves

d)an all purpose gas mask

3) People familiar with ammonia refrigeration systems become accustomed to its odor and may forget that the vapors

a)in a low concentration can cause death

b)will dissolve in pespiration and cause caustic burns

c)will burn or explode

d)all of the above

4) When the relief valve opens it discharges high pressure refrigerant vapor to the

a)liquid strainer

b)refrigerant inlet of the condenser

c)inlet side of the evaporator

d)suction side of the compressor

5) In a direct expansion type multi-box refrigeration system, the compressor is set up to cycle on and off by the

a)pressurestat

b)high pressure cut out

c)solenoid valve

d)low pressure cut out switch

6) Which of the listed operations will cause an automatically controlled refrigeration compressor to restart?

a)closing of the solenoid valve

b)closing of the expansion valve

c)an increase in the suction pressure

d)decreasing the suction pressure

7) In a direct expansion type cargo refrigeration system, a box is normally changed from chill to freeze by adjusting the

a)hand expansion valve

b)compressor suction valve

c)solenoid bypass

d)back pressure regulating valve

8)Which of the problems listed could be indicated if a sight glass in the refrigerant liquid line is full of bubbles?

a) excess refrigerant charge

b)faulty expansion valve

c)insufficient refrigerant

d)solenoid valve stuck open

9) A liquid indicator sight glass is useful in determining whether or not a refrigeration system is sufficiently charged. It is generally located in the

a)high pressure liquid line

b)low pressure liquid line

c)high pressure vapor line

d)low pressure vapor line

10) If the refrigeration compressor crankcase is sweating, the cause may be due to

a)a shortage of refrigerant

b)the compressor running continuously

c)liquid refrigerant returning to the compressor

d)the compressor short cycling on the high pressure cutout

11) If a refrigerating compressor crankcase is sweating, the trouble could be caused by

a)excessive superheat

b)a minor amount of air in the system

c)normal oil circulation with the refrigerant

d)the expansion valve being stuck in the open position

12) Frosting or sweating of the suction line of a reciprocating refrigeration compressor indicates a condition which could result in severe damage due to

a)minor amout of oil in the refrigerant

b)liquid slugging

c)insufficient refrigerant

d)a failed heat interchanger

13) Refrigeration system compressor crankcase sweating is an indication of

a)insufficient lube oil circulating throgh the system

b)excessive circulation of lube oil through the system

c)insufficient refrigerant in the system

d)an overworked compressor

14) Sweating of the refrigeration system compressor crankcase is caused by

a)too much superheat

b)insufficient superheat

c)suction pressure too low

d)excessive refrigerant returning to the compressor

15) Oil separators installed in refrigeration systems serve to

a)remove excess oil from the system

b)remove oil entrained in high pressure liquid line

c)return oil entrained in refrigerant vapor back to the compressor crankcase

d)all of the above

16) The oil separator (trap) used in a shipboard refrigeration system is located between the

a)compressor discharge valve and the condenser

b)condenser and the receiver

c)receiver and the king valve

d)receiver and the expansion valve

17) The purpose of the refrigeration system low pressure cutout switch is to

a)protect the compressor from liquid flood back

b)protect the compressor from low discharge pressure

c)start and stop the compressor upon system demand

d)-start the compressor after a drop in the evaporator pressure

18) The sensing line for the low pressure cutout switch to a refrigeration system is located

a)in the chill box

b)before the receiver

c)on the suction side of the compressor

d)on the discharge side of the compressor

19) The refrrigeration system low pressure cutout switch is actuated by

a)an electric system manager

b)a sensing bulb at the tail coil of the evaporator

c)pressure changes in the suction line

d)failure of the king solenoid valve

20)When you adjust thermostatic expansion valve

a)refrigerant must be bled off the sensing line before adjustments are made

b)all refrigerant must be pumped into the receiver before adjustments are made

c)time must be allowed for conditions to stabilize in the evaporator before further adjustments are made

d)all refrigerant must be routed through the dehydrator while changing the superheat setting

21) Low compressor head pressure in a refrigeration system can be caused by

a)insufficient condenser cooling water

b)excessive condenser cooling water

c)air in the refrigeration system

d)excessive refrigerant in the system

22) Which of the problems listed would cause the discharge temperature of an Freon refrigeration compressor to increase?

a)thermal expansion valve frozen open

b)suction gas heat exchanger bypassed

c)condenser clogged or fouled

d)high pressure cutout switch inoperative

23) One cause of high head pressure occurring in a refrigeration system can be

a)insufficient cooling water flow to the condenser

b)a low refrigerant charge in the system

c)the liquid valve is open too much

d)high evaporator superheat

24) If the head pressure of a reciprocating refrigeration compressor is excessive,

a)the relief valve should open before the high pressure cutout

b)the relief valve should open and allow the excess refrigerant to flow to the receiver

c)the high pressure cutout switch should operate before the relief valve opens

d)you should close in on a suction valve

25) If the refrigeration compressor was developing higher than normal discharge pressure, this could be a result of

a)air or noncondesable gases in the system

b)leaking discharge valves

c)leaking suction valves

d)liquid refrigerant flooding back from the cooling coil

26) If the water failure switch should fail to shut down the refrigeration compressor, the refrigerant pressure will build up in the high pressure side of the system to the point where the

a)compressor discharge valves would be damaged

b)condenser tubes would rupture

c)system relief valve would open

d)high pressure cutout switch would function

27) High suction pressure to a refrigeration system compressor is caused by

a)the expansion valve is insufficiently opened

b)the expansion valve being open too wide

c)the king valve is insufficiently open

d)a dirty dehydrator

28) If a refrigeration compressor had developed a high suction pressure, the problem could be a result of

a)a minor accumulation of air or uncondensable gases in the system

b)a leaking king valve

c)a clogged subcooler

d)liquid refrigerant flooding back from the cooling coil

29) Which of the conditions listed could cause excessively low refrigerant pressure at the compressor suction?

a)insufficient flow of condenser cooling water

b)the system is low on refrigerant

c)the solenoid valve to the chill box is "frozen" in the open position

d)the high pressure cutout switch is inoperative

30) Which of the conditions listed may be an indication of an excessive amount of refrigerant circulating through the system?

a)sweating of the compressor crankcase

b)colder than normal solenoid valve

c)frosting of the evaporator

d)weeping at the purge valve

31) Leaking suction valves in a refrigeration compressor are indicated by

a)higher than normal suction pressure

b)lower than normal suction pressure

c)lower than normal evaporator temperature

d)noticeable increase in compressor noise

32) If the discharge valves on the refrigeration compressor are leaking badly, the compressor should

a)run continuously

b)not start

c)have high discharge pressure

d)short cycle on the high pressure switch

33) If a refrigeration system were short of refrigerant, the condition would result in

a)continuous running of the compressor

b)high suction pressure

c)high discharge pressure

d)short cycling of the compressor on the water failure switch

34) A warmer than normal compressor suction line might be caused by

a)insufficient lubrication

b)insufficient refrigerant

c)excess refrigerant

d)excessive opening of the expansion valve

35) what causes the refrigeration system to short cycle on a HP cutout-

a)dischg valve leaking

b)pressure cutout set incorrectly

c)system overcharged with refrigerant

d)insufficient cooling water.

36) When purging a refrigeration system, the compressor is—

a)running

b)running but the condenser is secured.

c)shut down

d)running with the bypass open

37) The refrigerant temperature is at the maximum before it enters the—

a)expansion valve

b)compressor

c)condenser

d)evaporator

38) The solenoid valve controls the

a)pressure in the evaporator coils

b)amount of refrigerant entering the evaporator

c)flow of refrigerant to the expansion valve

d)amount of circ water to the condenser

39) Closing the solenoid valve will stop the compressor through the

a)low water pressure cut out switch

b)bypass relief valve

c)LP cutout switch

d)HP cutout switch.

40) The temperature bulb of the thermo expansion valve is attached to the

a)icebox coil

b)evaporator coil outlet

c)evaporator coil inlet

d)wall of the ice box

41) The temperature bulb of a solenoid valve is attached to the-

a)icebox coil

b)wall of the icebox

c)evaporator coil inlet

d)evaporator coil coutlet

42) The suction pressure regulating valve

a)cuts in the compressor

b)maintains the back pressure in the evaporator coils

c)cuts out the compressor

d)controls the expansion valve

43) The cooling water regulator is automatically actuated by

a)discharge pressure of the refrigerant

b)temperature of the refrigerant

c)an electric relay

d)a thermo relay

44) The LP control switch

a)is a safety device

b)actuates the coling water

c)cuts out the compressor to maintain proper flow.

d)regulates the king valve

45) A hot crankcase and cylinder head accompanied by low suction pressure would be caused by—

a)excess refrigerant

b)insufficient refrigerant

c)air in the system

d)stuck discharge valve

46) When securing a system the first step would be to—

a)open bypass valve

b)close receiver king valve

c)open solenoid valve

d)cut out compressor on HP

47) External frost on inlet of expansion valve indicates-

a)expansion valve plugged or dirty

b)head pressure too high

c)refrigerating comnpartment too cold

d)air in system

48) When the crankcase is cooler than the suction line it is because-

a)too much refrigerant

b)insufficient refrigerant

c)expansion valve open too wide

d)suction valve leaking

49) Closing the solenoid valve stops the compressor through the

a)HP cutout switch

b)low water pressure cutout switch

c)low pressure cutout switch

d)high water pressure cutout switch.

50) Tubing joints are –

a)brazed

b)welded

c)screwed

d)silver soldered

51) Which of the following would cause a compressor to run continiously-

a)LP switch jammed

b)HP switch jammed

c)clogged strainer

d)defective thermal bulb

52) The solenoid valve is a-

a)pressure controlled stop valve

b)temperature controlled stop valve

c)Freon controlled check valve

d)none of the above

53) The scale trap is located between the –

a)compressor and oil separator

b)expansion valve and evaporator coils

c)king valve and expansion valve

d)evaporator coils and compressor

54) Too low suction pressure could be caused by-

a)too much oil in the system

b)dirty scale traps

c)shortage of refrigerant gas

d)any of above

55) Sweating of a crank case is caused by-

a)too much oil in the system

b)too much superheat

c)insufficient superheat

d)expansion valve hung up

56) Slugging is usually caused by-

a)too much refrigerant in the system

b)too much oil in the system

c)expansion valve not operating properly

d)too much cooling water to condenser.

57) A device for holding open the suction valve and drawing gas from the suction manifold and returning it to the suction line without compressing is called-

a)relief valve

b)cylinder unloader

c)suction line bypass

d)dischg line bypass.

58) A hot suction line is caused by-

a)insufficient lubrication

b)insufficient refrigeration

c)too much refrigerant

d)expansion valve closed too much

59) If a solenoid valve is closed accidentally , the compressor would be stopped by-

a)automatic trip

b)low water cutout switch

c)low pressure cutout switch

d)HP cutout switch.

60)If the compressor short cycles on HP cutout, check for—

a)too much refrigerant in the system

b)condenser tubes need cleaning

c)system is starved of cooling water

d)all of above

61) If the compressor short cycles on LP cutout- the trouble could be

a)too much frost on evaporator coils

b)dirty traps and strainers

c)lack of refrigerant

d)any of above

62) If the compressor were to run continiously without lowering the temperature-the trouble could be—

a)leaky dischg valves

b)leak in the system

c)insufficient refrigerantd)any of above

63) Which of the following would cause a high suction pressure-

a)expansion valve open too wide

b)dirty dehydrator

c)king valve not open wide enough

d)expansion valve not open wide enough

64) If a compressor runs continiously , the cause might be-

a)clogged scale trap

b)stuck HP switch

c)defective thermal bulb

d)stuck LP switch.

65) Low suction pressure is caused by—

a)expansion valve causing flooding back

b)solenoid valve not functioning properly

c)leaky compressor suction valves

d)air in system

66) If the compressor dischg temp is higher than the receiver temperature-

a)add more refrigerant to the system

b)decrease the amount of cooling water to the condenser

c)increase the amount of cooling water to the condenser

d)remove some of the refrigerant from the system

67) Air can be prevented from entering into the system by-

a)running the refrigerant through an aereator

b)keeping the dehydrator clean at all times

c)keeping all glands and stuffing boxes on the HP side tight.

d)keeping all glands and stuffing boxes on the LP side tight

68) If there is too much Freon in the system—

a)the safety valve will discharge

b)the compressor will short cycle

c)the compressor will run continiously

d)it will mix with the oil in the crankcase

69) Frost on the outside of the thermal expansion valve is may be caused by-

a)too much superheat

b)air in the system

c)moisture in the system

d)any of the above

70) When starting a refrigeration system, always—

a)vent the evaporator

b)bypass the condenser

c)vent the condenser

d)none of the above

71) Solenoid valve controls the –

a)amount of refrigerant entering the evaporator coils

b)amount of refrigerant going to the expansion valve

c)amount of refrigerant going to the compressor

d)pressure of refrigerant going to the evaporator coils.

72) The solenoid valve is controlled by—

a)amount of liquid in the system

b)amount of gas in the system

c)temperature of the condenser

d)temperature of the icebox

73) A leaky dischg valve can be detected by

a)a drop in the icebox temperature

b)a dischg pressure lower than normal

c)a fluctuating high pressure guage

d)any of above

74) What will you do if the liquid start rising in the Surge Drum? (Direct cooling system)

a)Immediately reduce on the suction valve, and watch the Open more on the suction valve gauge.

b)Stop the compressor

c)It will never happen.

d)Open more on the suction valve.

75)Why is it so important to suck back as much freon liquid as possible from the evaporators, before stopping the compressor?

a)To prevent low condensing pressure during start up.

b)To prevent low suction pressure during start up.

c)To prevent freezing of line.

d)To avoid liquid coming back to the compressor during start up.

76)To get the best possible efficiency from evaporators, the superheat should be regulated to:

a)-5 to -10 deg C

b)+5 to 10 deg C

c)40 to 50 deg C

d)0 to 1 deg C

77)The thermoexpansion-valve does the following job--

a)Regulating freon liquid flow to the evaporator.

b)Regulating the freon flow to condenser.

c)Regulating cooling water temperature.

d)Regulating the suction pressure.

78)If the reefer plant has air in the system , from where will you vent the air out?

a)From the evaporator.

b)From the compressor.

c)From the receivers bottom.

d)From the condenser.

Answers:1c2a3d 4d 5d 6c 7d 8c 9a 10c 11d 12b 13b

14d 15c 16a 17c 18c 19c 20c 21b 22c 23a 24c 25a 26d 27b 28d 29b 30a 31a 32a 33a 34b 35a 36c 37c 38c 39c 40b 41b 42b 43a 44c 45b 46b 47a 48a 49c 50d 51a 52b 53c 54d 55a 56c 57b 58b 59c 60d 61d 62d 63a 64d

65b 66b 67d 68b69c 70c 71b 72d 73d 74a 75d 76b 77a 78d

1)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

2)Which of the listed types of gasket material should be used on high pressure fuel oil lines on a diesel engine?

a)Fiberglass

b)Sheet asbestos

c)Neoprene

d)Soft copper

3)While inspecting the main bearings on a diesel engine you find impregnated dirt and scratches in the bearing surface. You would, therefore, suspect that

a)the bearing had been overheated

b)water was present in the oil

c)the lube oil was not being properly filtered

d)the maximum allowable bearing pressure had been exceeded

4)If the coolant temperature is excessively low as it passes through the internally cooled fuel injectors, the injectors maybe damaged by

a)water condensation in the fuel

b)corrosion of the nozzle tip

c)carbon deposits on the leakoff inlet

d)over lubrication of the needle valve

5) A cracked cylinder head on a diesel engine may be indicated by

a)excessive lube oil consumption

b)water draining from the fuel leak off valves

c)combustion gases venting at the expansion tank

d)excessive fuel oil consumption

6)The principal hazard to personnel when a diesel nozzle tester is in use is

a)electrical shock

b)toxic fumes

c)explosion

d)blood poisoning

7) Which of the listed cylinder liner surface conditions indicates proper lubrication?

a)dull black appearance

b)bright appearance

c)thin layer of lacquer

d)thick oily film

8)Because of the tolerances used in diesel engine fuel oil pumps, a worn plunger requires

a)grinding the spare plunger to the barrel

b)replacing the plunger and the barrel

c)highly polishing both the plunger and barrel

d)replacing plunger only

9)A well lubricated bearing surface always appears

a)well knurled

b)slightly streaked

c)lightly glazed

d)highly polished

10)Uneven bolt tightening during the installation of a fuel injection pump can result in

a)binding of pump moving parts

b)ignition delay

c)high tortional shock to the fuel lines

d)improper pump-to-engine timing

11)Which of the listed devices could be used as a substitute for a ring groove tool?

a)steel brush

b)fine emery cloth or steel wool

c)a section of the removed compression ring

d)a case hardened scraper

12)After a long period of operation, a wear ridge, caused by piston ring action, will develop near the top of the cylinder liner. This ridge must be removed when piston rings are renewed in order to prevent

a)excessive wear during the seating period

b)excessive lubrication of the top ring

c)improper spreading of lubrication on the cylinder wall

d)breaking of the top ring, ring land, or both

13)A properly honed diesel engine cylinder liner will

a)prevent piston ring wear

b)shorten the ring break-in period

c)prevent cylinder liner glazing

d)appear slick and glaze

14)A diesel engine fails to start because of water in the fuel. In order to start the engine, you should

a)turn engine with jacking gear

b)drain filters and strainers and bleed off water at each injection pump

c)blow through the cylinders and fuel lines with a drying agent

d)all of the above

15)If the piston ring gap remains insufficient when installing new rings, you should

a)install oversized rings

b)hone the cylinder liner to allow ring installation

c)compress the rings tighter with a compressing tool

d)file the ends of the rings

16) When installing rings on a diesel engine piston, you should check the ring

a)diametrical tension

b)gap clearance

c)radial thickness

d)face thickness

17)You are installing new piston rings on a single acting diesel engine piston. To check the ring gap clearance, the rings should be placed at the

a)point of minimum cylinder wear

b)center of the cylinder

c)point of maximum cylinder wear

d)point of maximum ring wear

18)Which of the copper alloys listed is commonly used in heat exchangers and possesses a high resistance to corrosion?

a)red brass

b)manganese bronze

c)copper beryllium

d)cupro-nickel

19)After installing a new hydraulic pump in a system, what special attention should be given to the hydraulic system?

a)the relief valves in the system should be readjusted

b)-the filters and strainers should be checked frequently

c)all system pressure should be readjusted

d)the system should be drained and renewed with a fluid of different operating characteristics

20)Moisture and impurities can be removed from pneumatic system by using

a)air intake heaters

b)desiccated suction strainers

c)multi-orificed suction valves

d)blowdown valves and filters

21) Clearances between the impeller hub and casing of a centrifugal pump are checked with the use of

a)wooden wedges

b)an accurate set of feeler guages

c)a machinist's rule

d)a depth micrometer

22)Copper sheet metal that is to be used as a gasket, is usually annealed by heating it to a cherry red color, and then

a)dousing it in cold water

b)cooling it slowly in air

c)quenching it slowly in oil

d)drawing its temper quickly

23) which is not correct—soon after the bridge gives FWE after berthing, the duty engineer usually—

a) puts off the aux blowers

b) puts ME on turning gear

c) opens scavenge and turbocharger drains

d) puts off the boiler water circulating pump.

24) All steam valves over 6” in dia must be fitted with

a)rising stem type valve

b)bypass line and valve

c)flange unions

d)steam lagging

25) A CO2 fire extinguisger must be recharged when it is found to be

a)15% below weight

b)5% below weight

c)20% below weight

d)10% below weight

26) Between the time of fixed CO2 alarm signal and actual delivery of CO2 to the system there is a time delay of

a)20 seconds

b)60 seconds

c)2 minutes

d)no delay

27) A canister type gas mask works on the principle of

a)filtering

b)chemical combination

c)aBsorbsion

d)all of above

28) The canister of an all purpose gas mask is installed by

a)removing top seal and inserting

b)removing bottom seal and inserting

c)removing top seal , inverting and inserting

d)removing top and bottom seals inverting and inserting

29) Which of the following valves is not contained in a SCBA set mouth piece

a)inhalation

b)saliva

c)exhalation

d)reducing

30) The reducing valve in a SCBA set reduces the pressure from 180 bars to

a)1.5 bar

b)1 bars

c)0.25 bars

d)0.05 bars

31) Death due to electrical shock will happen at a minimum value of

a)0.2 amperes

b)1 amperes

c)2 amperes

d)10 amperes

32) Diesel engine pistons are usually concave in shape because

a)it gives more volume of air

b)for conical atomization

for squish effect

d)all of the above

33) The diesel engine cylinder is secured at

a)the top end

b)bottom end

c)both ends are not secured

c)both ends are secured

34) The purpose of a silencer on the engine exhaust is to

a)deaden the explosive sounds

b)reduce the speed of the exhaust

c)reduce the temperature of the exhaust

d)all of above

35) The following valves in a 4 stroke engine are cam operated

a)inlet and exhaust

b)fuel

c)air starting

d)all of the above

36) following valves in the 2 stroke engine may not be cam operated

a)fuel

b)air starting

c)exhaust

d)supercharging

37) When there is carbon monoxide in the exhaust gases of a diesel engine

a)the air supply is in sufficient

b)carbon remains unburnt and passes off as soot

c)less heat is developed to be converted to work

d)all of above

38) Which of the statements is not true

a)the mean cylinder temperature of a 2 stroke engine is higher than a 4 stroke engine

b)the exhaust temperature of a 2 stroke engine is higher than a 4 stroke engine

c)in a 2 stroke engine there is a power stroke every revolution and hence less time to dissipate heat

d)the low temperature scavenging air dilutes exhast gases lowering exhaust temperatures in a 2 stroke engine

39) Which of the statements regarding journal loads are not true

a)in a 2 stroke engine the bottom half of the crank pin bearing takes the whole wear

b)in a 2 stroke engine the bottom half of the main bearings receives the whole wear.

c)in a 4 stroke engine the crank pin bearing wear is divided but the top half receives a greater wear than the bottom half

d)in a 4 stroke engine the main bearing wear is divided but the bottom half receives a greater wear than the top half.

40) If there is afterburning in the cylinder or combustion takes place after the fuel injection valve closes, then which of the following is not true

a)combustion does not continue during expansion period of stroke

b)break down of MECYL lubrication takes place

c)overheated exhaust ports on 2 stroke engines

d)danger of exhaust trunk fires

41) Dribbling nozzles can cause-

a)after burning

b)detonation and crankcase dilution

c)loss of power

d)all of above

42) What could cause explosions of air compressor -

a)operating in inflammable fumes

b)intercooler or after cooler tubes getting holed

c)leaky oil or compression rings

d)all of above

43) The pipe from the air compressor to the air receiver should be

a)larger than the compressor discharge opening

b)smaller dia than the compressor discharge opening

c)same size

d)none of the above

44) What are the principal causes of air compressor valve and seat erosion

a)wire drawing of damp air

b)carbon formation

c)dusty intakes

d)all of above

45) What are the causes of air compressor overheating

a)broken valve strips

b)wrong direction of rotation

c)filter clogged

d)all of above

46) When you lay up a ship, like a FPSO, what precautions will you take with the cooling water system

a)there is no need for any precautions

b)keep the system full of fresh water

c)keep the system clean and dry

d)keep system full of solvent

47) What can reduce ignition lag in a ME cylinder

a)increase in compression ratio

b)increase in he air intake temp

c)overturbulence

d)all of above

48) On diesel generator which share load , the governor

a)speed droop is permanent

b)speed drop is adjustable

c)speed droop is not necessary

d)none of the above

49) The 2 stroke engine never has engine driven centrifugal blowers because

a)the air pressure developed is proportional to the square of the engine rpm

b)at low speeds the scavenge air pressure is too less

c)at high speeds the scavenge air pressure is too great

d)all of above

50) It is better to provide a large volume of cooling water with a slight temperature differential between inlet and outlet cooling lines , than to provide a lesser but colder flow, with the same outlet temp

a)to avoid vapour pockets and local hot spots

b)to avoid scale deposition

c)to avoid thermal shock to liner due to cold water inlet

d)all of above

51) Which of the following is not true

a)lubrication of a piston pin bearing is more efficient than a journal bearing

b)piston pin bearing has a rotary swinging motion

c)journal bearing has a rotary motion

c)there is no difference in lubrication efficiency

52) The inability of a governor to change the speed when a new load requires a change is called

a)deadbeat

b)hunting

c)instability

d)pooped

53) Which of the following is true

a)oil scraper rings used with splash lubrication system has the sharper edge downwards towards the crankcase

b)oil scraper rings used with individual lubricators have the sharper edge down wards .

c)there is no difference whether it is splash or individual the sharp edge is always downwards

d)there are no sharp edges for scraping or oil control

54)Sea water has ppm salt

a)330 ppm

b)3300 ppm

c)33000 ppm

c)33 ppm

55)Select the nearest values. 1 HPa is

a)1000 mb

b)760 mm of Hg

c)1 atmosphere

d)all of above

56)Select the nearest values. 1 KPa is

a).01 kg

b)100 mm Aq

c).01 bars

d)all of above

57)Select the nearest value. 1 MPa is

a)10 kg

b)100 metres Aq

c)10 atmospheres

d)all of above

58)Select the nearest value. 1 KN/ M2 is

a)1KPa

b).01 kg

c)0.147 Psi

d)all of the above

59)In a “moment balance” type pressure transmitter, there is a balance between the input force and the balance force. The position is converted to pressure by the

a)pneumatic pilot relay

b)bellow

c)spring

d)flapper and nozzle

60)In a “ force balance” type differential pressure transmitter, when high pressure pushes the force beam, the flapper is pushed away from the nozzle. The balancing pressure will increase and move flapper

a)towards the nozzle

b)away from the nozzle

c)flapper maintains position

d)towards the diaphragm link

61)In a purged pipe liquid level measurement system , air is constantly bubble out from the

a)static line

b)standpipe

c)balance line

d)sight flow indicator

62)A pitot tube which works on kinetic energy displays

a)friction head

b)velocity head

c)pressure head

d)proportional head

63)A pitot tube which works on friction head displays

a)pressure drop

b)velocity drop

c)vacuum head

d)none of above

64)A pressure to position converter there is

a)a single input bellow

b)a single balance bellow

c)a input bellow and a balance bellow

d)no bellows at all supporting the force beam

65)According the Bernoulle’s theory the sum of the following is a constant

a)pressure head and velocity head

b)gravity head and vel head

c)pressure head and gravity head

d)none of the above

66)For an instrument calibrated by iso-Butane 100% LEL is how much by volume of HC

a)1.8%

b)1%

c)10%

d)none of above

67)one Micron is how much in terms of millimeters

a)1/ 1000 mm

b)1/ 100 mm

c)1/ 10000 mm

d)1/ 10 mm

68)1% of LEL is

a)10 ppm

b)100 ppm

c)1000 ppm

d)1 ppm

69)1% by volume of HC is

a)10000 ppm

b)1000 ppm

c)100 ppm

d)100000 ppm

70)1 ppm of chlorides in water means

a)1 mg/ litre

b)1 mg/ cum

c) 1 mg/ cc

d)none of above

71) With the compensating needle screw of a Woodward regulator is closed, what will happen when the load is changing?

a)Woodward regulator will regulate very slowly

b)Woodward regulator will regulate very fast

c)Woodward regulator will not regulate at all

d)Woodward regulator will regulate normally

ANSWERS

1A 2D 3C 4B 5C

6D 7B 8B 9D 10A 11C 12D 13B 14B 15D 16B 17A 18D 19B 20D 21B 22B 23D 24C 25D 26A 27D 28D 29D 30C 31A 32D 33A 34D 35D 36C 37D 38C 39A 40A 41D 42D 43C 44D 45D 46C 47D 48B 49D 50D 51A 52A 53A 54C 55D 56D

57D 58D 59A 60A 61B 62B 63A 64C 65D 66A 67A 68B 69A 70A 71A

QUESTIONS:

1) The flash point of a residual fuel oil should be used to determine the highest temperature to which the oil may be heated

a)for atomizing

b)for centrifuging

c)in a storage tank

d)in the recirculating line

2)Oil or scale deposits on boiler tube walls will cause

a)those tubes to overheat

b)decreased boiler steam pressure

c)increased boiler steam pressure

d)an explosion in the boiler

3)Normally a boiler water sample should be taken

a)after the boiler has been blown down

b)before the boiler has been blown down or chemicals added

c)when the boiler has been refilled with makeup

d)from the highest point in the feed system

4)A lower than normal boiler stack gas temperature usually indicates

a)dirty firesides

b)dirty watersides

c)fuel high sulphur content

d)incomplete combustion

5)Boiler screen tubes are used to protect which of the listed components from high furnace temperature?

a)Superheater

b)Refractory

c)Wall tubes

d)Steam drum

6)Modern fuel oil temperature control devices are regulated to obtain a desired viscosity rather than a specific fuel oil temperature because

a)residual fuel oils have the same viscosity characteristics regardless of they are refined

b)the temperature of the fuel oil varies with the flow rate through the heater

c)the relationship between temperature and viscosity varies with different fuels

d)viscosity regulation eliminates the need for close control of the fuel/air ratio

7)The most harmful slag forming compounds found in fuel oils are

a)iron and sulphur

b)vanadium and sodium

c)potassium and nickel

d)calcium and silica

8)Which of the following procedures decreases the total dissolved solids concentration in the water of an auxiliary boiler?

a)Hydrazine treatment of condensate

b)Frequent compounding

c)Chemical cleaning

d)Bottom blowing

9)The purpose of the programmed purge cycle on an automatically fired auxiliary boiler is to

a)cool the furnace to prevent pre-ignition

b)remove explosive vapors from the furnace

c)evaporate accumulated unburned fuel oil

d)provide sufficient air in the furnace to allow ignition of the fuel

10)Automatic combustion control systems for some auxiliary boilers are designed to cycle burners on in response to

a)low fuel pressure

b)fuel return pressure

c)low steam pressure

d)furnace air pressure

11)When it becomes necessary to replace any tubes in a water-tube auxiliary boiler to eliminate leaks at the tube seats, the replacement tubes should be

a)stress relieved to ensure expansion when rolled

b)annealed to prevent cracking when rolled

c)fitted with a welded backing ring in the seat area

d)rolled, beaded, and seal welded around the bead edge

12)Which of the following items is necessary for all waste heat boiler installation, regardless of design or manufacturer?

a)Control of evaporation

b)A separate means to prevent feedwater contamination

c)Power circulating pump

d)Superheater

13)When a waste heat boiler is installed in the exhaust of a main position diesel engine, the exhaust gas bypass would be issued

a)at high loads to prevent overheating

b)at low loads to prevent corrosion in the boiler

c)during periods of high steam demand

d)when the turbocharger is in operation

14)The flame safeguard control system of a large automatic auxiliary boiler will provide fuel shut off in the case of high

a)water

b)voltage

c)fuel pressure

d)steam pressure

15)A feed pump for an auxiliary boiler might lose suction if the

a)boiler water level is low

b)feedwater is too hot

c)boiler steam demand is low

d)feedwater is too cold

16)Generating tubes in waste heat boilers are finned to

a)reduce gas flow turbulence

b)prevent exhaust gas corrosion

c)increase the rate of combustion

d)increase the rate of heat transfer

17)Combustion control systems on automatic boilers are designed to prevent immediate burner ignition after a normal or safety shutdown in order to allow time for

a)the furnace to be purged

b)electric charge buildup in the igniter

c)the fuel pump to start

d)the drum level to equalize

18) Dissolved oxygen can be removed from the boiler water by

a)frequent surface and bottom blows

b)dumping and refilling the boiler weekly

c)passing the water through absorbent filters

d)treating the water with chemical scavengers

19)A continuous blow is used to

a)regulate the density or salinity of boiler water

b)remove scum from the surface of boiler water

c)permit air to excapewhile raising steam in a cold boiler

d)remove sludge from the bottom of the water drum

20)A photoelectric cell installed in an automatically fired auxiliary boiler burner management system

a)opens the burner circuit upon sensing a flame failure

b)detects a flame failure by monitoring radiant heat from glowing refractory

c)requires mechanical linkage to secure the burner fuel supply

d)must be bypassed at low firing rates

21)The end product of reactions occurring when boiler water is chemically treated, remain in the boiler and increase the need for

a)acid cleaning

b)makeup feed

c)boiler blowdown

d)waterside corrosion treatment

22)When the flame scanner senses flame failure during boiler operation, which of the listed events will occur FIRST?

a)The fuel oil service pump is stopped.

b)The automatic purge cycle commences.

c)The fuel oil solenoid valve is de-energized.

d)The "trial for ignition" period commences.

23)As the percentage of CO in the stack gas decreases, you can assume that

a)the fuel to air ratio is increasing

b)fuel is being burned with increasing economy

c)you are approaching secondary combustion

d)excess air is increasing

24)Which of the listed types of strainers are installed between the fuel oil heater and the burner manifold?

a)Duplex

b)Magnetic

c)Simplex

d)Self-cleaning

25)The greatest deterrent to heat transfer from the fireside to the waterside of a boiler is

a)water film

b)water eddies

c)gas film

d)gas eddies

26)High stack temperature occurring in an auxiliary boiler could be a result of

a)insufficient air for combustion

b)complete combustion in the furnace

c)secondary combustion in the uptake

d)high fuel oil temperature

27)Oxygen corrosion in auxiliary boilers is prevented by treating the boiler feed tank with either sodium

a)sulfite or hydrazine

b)sulfite or hygroscopic sulfite

c)bromide or hydrazine

d)bromide or hygroscopic sulfite

28)Radial cracks have developed in the castable refractory of the burner cones after the first firing since the installation of new furnace front refractory. This is an indication of

a)a need for plastic firebrick patchwork

b)inadequate cone angle

c)a need for castable refractory patchwork

d)relieved stresses

29)In most marine boilers, the primary reason the first few rows of generating tubes, called screen or furnace row tubes, are made larger than the rest of the generating tubes is because

a)they require more water flow since they are exposed to the greatest heat

b)they must screen the superheater from the direct radiant heat of the burners

c)they must act as downcomers to ensure proper circulation

d)their main function is to retard combustion gas flow for maximum heat transfer rates

30)Boiler efficiency and its ability to absorb heat is limited by the need to

a)maintain an excess of CO during transient firing rates

b)prevent excess air density at low load conditions

c)protect the safety valves from excessive temperature

d)maintain uptake gas temperature above the dew point

31)Panting in an oil fired marine boiler can be caused by

a)excessive combustion air supply

b)low fuel oil temperature

c)fouled burner sprayer plates

d)insufficient combustion air supply

32)The MOST common cause of heat blisters developing on boiler generating tubes is due to

a)waterside deposits

b)fireside deposits

c)low water level

d)insufficient water circulation

33)While the vessel is rolling in heavy seas, the level in the boiler gage glass remains steady, this is an indication of

a)the gage glass is functioning normally

b)there is most likely an obstruction in the lower valve

c)the steam drum is adequately baffled

d)the water level in the steam drum is too low

34)Oil deposits can be removed from the waterside of boilers by "boiling out" with a/an

a)alkaline solution

b)acid solution

c)salt solution

d)kerosine solution

35)Oxygen content of boiler feed water at 50C is –

a)same as water at 90C

b)twice more than water at 90C

c)thrice more than water at 90C

d)4 times more than water at 90C

36)In a boiler furnace, which statement is true

a)the waterwall protects the refractory

b)the refractory protects the water wall

c)where there is refractory there is no waterwall

d)none of above is true.

37)The purpose of a superheater in a boiler is

a)to get more steam as steam is in contact with water

b)to get higher pressure steam

c)to get more heat on steam at lower pressures

d)to get wet steam

38)The bottom blow to remove solid matter ( not salinity ) of boiler is done by

a)one short blow with boiler running

b)one long blow with boiler cut off

c)several short blows when boiler is cut off

d)several short blows with boiler running.

39)On a chemical tanker discharging palm oils in Baltic in winter, some palm oil traces are found in the hotwell. This will cause –

a)foaming in the boiler

b)fluctuating water level in drum

c)wet steam on deck

d)all of above

40)Excellent combustion in a boiler furnace is indicated by , the % of gases in funnel stack as follows

a)CO/ Zero %

b)CO2/ 14%

c)oxygen/ 5%

d)all of above

41)A boiler safety valve which has popped several times in succession—

a)will have same popping pressure

b)popping pressure will become progressively higher

c)popping pressure will become progressively lower

d)lower first and then higher

42)What when present in boiler feed water causes scaling

a)sodium carbonate

b)sodium suphate

c)calcium sulphate

d)hydrazine

43)Impurities in boiler feed water causes-

a)scale formation

b)corrosion

c)water carry over

d)all of above

44)Water carry over in boiler steam can be caused by

a)high concentration of dissolved solids

b)high alkalinity of feed water

c)high concentration of suspended solids

d)all of above

45)If oil enters the boiler, it will coat the

a)top tubes

b)bottom tubes

c)both top and bottom

d)middle tubes

46)The boiler superheater safety valve is set at

a)higher pressure than the drum safety valve

b)lower pressure than the drum safety valve

c)same pressure

d)can be higher or lower

47)the purpose of a water wall in a boiler is to—

a)it increases the boiler capacity

b)it reduces maintenance to the refractory

c)it increases heating surface

d)all of above

48)What are the causes of refractory failure in a boiler

a)warming up of boiler too quickly

b)leaving air register open when the flame is cut out

c)failure to repair cracks when inspecting furnace

d)all of above

49)Carbon on the atomizer tip of a boiler is not indicated by -

a)low fuel oil temperature

b)low fuel oil pressure

c)cold air

d)diffuser plate out of place

50)Adding Hydrazine hydrate N2H2 to boiler water

a)removes oxygen

b)makes iron oxide sludge non adherent

c)increases alkalinity

d)all of above

51.After closing the drain during the blowing procedure for a glass water gauge, the water cock is opened and the water flows to the top of the glass. Then the steam cock is opened and the water flows down and out of the glass; Which of the following statements are correct?

The water level is between the water cock connection of the boiler, and the bottom of the gauge glass. It is safe to put feed water into the boiler.

The water level in the boiler is below the water cock connection of the boiler. It is unsafe to put feed water into the boiler.

The water level is above the steam cock connection of the boiler. There is a danger of priming the boiler if any additional feed is put into it.

The water level is normal, but it requires time for the gauge glass to stabilise. It is safe to put feed water into the boiler.

52.Feed check valves for main and auxilliary purposes are normally of the double shut off type, as shown in the diagram. What is the main function of the non-return valve?

To prevent the steam and water in the boiler from discharging out by the feed line, if a feed line fracture or a joint in the line blows.

To allow overhaul of the screw down valve when the non-return valve is shut and the boiler is steaming.

To increase the workload for staff when overhauling the boiler.

To allow fine tuning of feed water flow to the boiler.

53.If inspection or repair of the boiler is due, the plant has to be shut down, and the boiler emptied for water. If time is available, which of the following procedures are correct?

The boiler be blown down to sea immediately after shut down.

The boiler be allowed to cool down by its own after shut down. Then pump the water out.

The feed water regulator to be bypassed and the boiler topped up with cold feed water immediately after shut down.

The safety valve easing gear be operated and all the pressure released immediately after shut down.

54.Classification societies require that when initially fitted to a boiler, safety valves must be subjected to a test of accumulation of pressure. Is this to:

See how high the boiler pressure will go before the safety valve operates.

See at what pressure the safety valve will reset.

Ensure the valves are of the correct discharge capacity for the boiler.

Ensure the maximum firing rate can keep the pressure above normal working pressure

55.The principal objects for boiler feed water treatment should be:

Prevention of corrosion in the boiler and feed water system by maintaining the boiler water in an alkaline condition and free from dissolved gases.

Control of the sludge formation and prevention of carry over with the steam.

Prevention of scale formation in the boiler and feed water system by (a) using distilled water or (b) precipitating all scale forming salts into a non-adherent sludge.

All of the mentioned reasons.

56.The boiler have been shut down completely for inspection and repair. You have finished work and are going to start firing the boiler. What is the correct procedure for heating a boiler from cold?

Start the firing on maximum rate and raise the pressure in as short a period as possible, to save energy.

Start the firing on minimum rate and alternate with maximum rate continuously firing until the boiler is up to pressure.

Start the firing on minimum rate and continuously fire until boiler is up to pressure.

Start with intermittent firing, using small firing periods and long intervals gradually building up to longer firing periods and shorter intervals.

57.After obtaining permission from the duty Deck Officer, under what conditions would the process of soot blowing the boiler tubes be most beneficial?

When the boiler is firing on high rate.

When the boiler is firing on low rate.

When the boiler is firing on medium rate.

When the boiler is standing idle.

58.Which of the following is not a principle of heat transfer utilised in a boiler?

Convection.

Conduction.

Ionisation.

Radiation.

59.Low temperature corrosion can occur in both oil fired and exhaust/waste heat recovery boilers. Considering a fuel with same sulphur content, the air/fuel number,lamda, in a combustion process also indicates a relation to what temperature sulphuric acid condensates. What is the correct relation between air/fuel ratio and low temperature corrosion?

High air/fuel ratio rises the condensation temperature, and thereby reducing the safe limits between normal operation and condensation temperature.

High air/fuel ratio rises the air speed and thereby lowers the pressure and temperature so sulphur acid condensates.

High air/fuel ratio does not contribute significant to change of condensation temperature.

High air/fuel ratio lowers the boiler temperature causing the sulphur acid to condensate.

60.An expansion process along a turbine venturi is ofthen recognized as if no heat transfer out of the system is occuring What is the correct term for this?

.

Isochorie.

Adiabatic.

Isobar.

Endothermic

61.Most boiler design incorporate external "downcomers". For what purpose are those "downcomers" primarely incorporated?

To increase heating surface area.

Ensure adequate circulation in all conditions of steaming.

Provide extra support for furnace tubes.

None of above

62.For what purpose is a "de-aerator" in a boiler feed water system used?

Removal of excess nitrogen in the feed water.

Removal of excess sulphur in the feed water.

Removal of excess hydrogen in the feed water

Removal of excess oxygen in the feed water.

63.Waste heat recovery is important to save energy. By using the hot exhaust gases from main and auxiliary engines, the energy is transferred to the steam system by the waste heat boiler. Low output from engines, and low funnel temperatures can make area finned surfaces. What kind of acid would be present?

Sulphuric acid.

Hydrochloric acid.

Nitric acid.

Ascorpic acid.

64.Fluctuation of high temperatures under flame impingement, makes the surface of the firebrick breaking away in layers. What is the correct engineer term for this?

Spewing.

Slopping.

Slagging.

Shrinking.

65.Which of the below statements characterizes the most significant differences between a water-tube boiler and a fire-tube boiler during operation?

The watertube boiler can tolerate a short period of time without any water, when the oilburner is still in action.

Water-tube boilers are more efficient and contains less water. They suffer from major damages when run dry during operation.

The firetube boiler does not need any non-return valves in the feedwater line circuit.

The firetube boiler has a much better capability to work at higher steam pressure.

66.Quality of the feed water in a steam plant changes during operation. Caused by this, the water is regularly tested. Which of the below statements describes the chemical mechanisms normally occuring?

Generation of carbonic acid causes the water quality to drift towards sour and lower the pH - number.

Generation of sulphur acid causes the water quality to drift towards sweet and rise the pH - number.

All of the mentioned alternatives.

Water is becoming sligthly less conductive and does not transfer heat.

67.You are going to start firing a boiler. Which of the below mentioned alternatives do you consider as most important?

Opening the main steam pressure outlet valve.

Activating the main safety valves.

Bottom-blowing the boiler to be absolutely convinced that water is present in the boiler.

None of the above

68.Which feedwater condition would you prefer?

pH value 7.5

Rich on H2 C5 OH

Rich on oxygen.

Slightly salt.

69.What is the main purpose of bottom-blowing a boiler?

To control that water is present in the water chamber, when the boiler is in active operation.

To adjust steam pressure when the burner capacity is excessive.

To check that we do not have any leak of smoke and gases in the combustion camber.

To get rid of sludge in the water chamber

70.What is an effective means of measuring total dissolved solids in boiler water?

Conductivity test.

Alkalinity test.

Chloride test.

Not possible to test solids in boiler water.

71.What initial simple recommendation can we give to reduce oxygen in the boiler water?

Lower the feed water temperature.

Increase the boiler pressure.

Increase the "Blow down".

Raise the feed water temperature.

72.What is the correct PH-value for the Boiler Water?

8,3 - 9.

4,5 - 6.

Below 4,5

9 - 11.

73.What will you do if the PH-value in the boiler water is over 11?

Increase the dosage of chemicals.

Decrease the dosage of chemicals.

Blow the boiler and renew water until the PH-value is normal again

Nothing.

74.Which of the below listed effects can be caused by the presence of Calcium in the boiler water?

Loss of alkalinity, corrosion of boiler metal surfaces, and loss of phosphate reserve in the boiler.

Passifying of boiler metal surfaces.

Increase of alkalinity and PH-value.

No negative effects.

75.For a low pressure boiler, after testing the water cloride level, it is found to be 500 PPM, what action would you take?

Blow down boiler and check condenser for leakage.

Do nothing.

Decrease dosage.

Increase dosage.

76.If oil is found in the boiler water, what action would you take other than isolating the leak?

Dose with coagulent and blow down the boiler.

Blow down the boiler.

Do nothing.

Dose with coagulent.

77.At what interval should boiler water testing usually take place?

Every month

Every watch

Every day.

Every 3 months

78.In a low pressure auxiliary boiler, what would you consider to be the maximum allowable chloride level?

300 PPM.

2 PPM

3 PPM

18 PPM

79.In a low pressure auxiliary boiler, what would you consider to be the normal operating range of phenolphthalein alkalinity ?

100 - 300 PPM CaCO3.

2- 8 PPM

0.5 -2 PPM

8- 25 PPM

80 Testing feed and main boiler water condition and adjusting water treatment must be done , as per class rules —

a)every 4 hourly watch

b)once a month

c)once a week

d)every 24 hrs

81 Boiler water reading records shall be available on board ,as per class rules of –

a)chlorides/ phosphates

b)pH

c)Oxygen

d)All above

82 Common chemicals used to prevent formation of boiler tube scales are

a)calcium phosphate

b)magnesium hydroxide

c)sodium chloride

d)sodium phosphate

83 Thermal deaeriation in cascade tank/ hotwell removes dissolved oxygen up to—

a)10%

b)50%

c)95%

d)75%

84 Oxygen remaining after thermal deaeration is removed by chemical scavenging using

a)Hydrazine

b)sodium phosphate

c)sodium hydroxide

d)caustic soda

85 Sodium sulpite chemically combines with oxygen to form—

a)Nil dissolved solids

b) dissolved salts

c)nitrogen

d)none of above

86 Hydrazine causes—

a)cancer

b)tuberculosis

c)asthma

d)safe for use

87 Water / steam side of boiler is passivated at pH

a)3.5 to 5

b)10 to 11

c)13 to 14

d)7

88 Alkaline water changes from pink to colourless phenolphethelein at

a)8.3

b)12.9

c)1.8

d)2.9

89 Boiler water is tested for correct alkalinity to—

a)precipitate hardness salts to prevent scale

b)passivate with Fe3O4 film

c)maintain silica in solution to prevent scale

d)all above

90 Feed water and condensate pH value should be—

a)11 to 12.1

b)8.3 to 9

c)7 to 7.3

d)6.4 to 7.6

91 Boiler water pH should be in the range of

a)8 to 8.9

b)9.5 to 11

c)3.4 to 5.8

d)13 to 13.2

92 Cooling fresh water pH value should be-

a)8.3 to 10

b)12 to 13.1

c)5.2 to 7.1

d)7

93 Boiler feed water chloride value should be less than

a)0.249 ppm

b)3 ppm

c)15 ppm

d) 200 ppm.

94 Cooling fresh water ppm for chlorides should be max—

a)50

b)300

c)3

4)0.249

95 Hydrazine does the following—

a)scavenged dissolved oxygen

b)reduced red oxide to black oxide

c)raises the pH of condensate and feed water systems

d)all of above

96 Boiler feedwater testing is for—

a)hardness

b)oxygen

c)chlorides

d)all above

97 Factors affecting boiler water tube corrosion are

a)cavitation

b)dissolved solids gases

c)micro organisms

d)all of above

98 Condensate testing is for

a)pH

b)chlorides

c)ammonia

d)all above

99 The main purpose of boiler water treatment is to—

a)reduce hardness

b)increase pH

c)remove oxygen

d)all of above

ANSWERS:1C2A3B4D5A6C 7B 8D 9B 10C 11D 12A 13B 14D 15B 16D 17A 18D 19A 20A 21C 22C 23D 24A 25C 26C 27A 28D 29A 30D 31D 32A 33B 34A 35D 36A 37C 38C 39D 40D 41C

42C 43D 44D 45B 46B 47D 48D 49D 50D 51A 52A 53B 54C 55A 56D 57A 58C 59A 60B 61B 62D 63A 64C 65B 66A 67A 68A 69A 70A 71D 72A 73C 74A 75A 76A 77C 78A 79A 80D 81D 82D 83A 84B 85A 86B 87A 88D 89B 90B 91A 92C

93A 94D 95D 96D 97D 98D 99D

MAIN ENGINES

1) Friction developing between the moving parts of a governor, governor linkage and control valve will cause the governor to

a)react with insufficient speed droop

b)fail to react to small speed changes

c)have excessive sensitivity to small speed changes

d)remain in the neutral position

2) A large change in ambient temperature, or using an oil of a viscosity different than the one recommended by the manufacturer in a mechanical hydraulic governor, will result in the need to adjust the

a)pilot valve opening

b)compensating needle valve

c)compensating spring tension

d)accumulator spring tension

3) 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

4) When the prime movers of two paralleled generators, equipped with mechanical-hydraulic governors, are operating within their designed range, the unit with the least amount of speed drop will

a)pick up more of any increase in load

b)pick up less of any increase in load

c)share an equal amount of any increase in load

d)drop an equal amount of any decrease in load

5) Clearance volume scavenging in a turbocharged, four-stroke/cycle diesel engine is accomplished

a)during the valve overlap period

b)with only the exhaust valve open

c)at a pressure below atmospheric

d)without cooling the cylinders or pistons

6) Trunk-type diesel engine pistons are most effectively cooled by heat

a)conducted through the engine block

b)conducted to water cooled cylinder walls

c)conducted through the piston crown

d)losses to escaping exhaust gasses

7) Fuel oil is injected into the cylinder of a four-stroke/cycle diesel engine during the

a)intake stroke

b)exhaust stroke

c)power stroke

d)compression stroke

8) A large, low-speed, main propulsion diesel engine uses sea water to directly cool the

a)cylinder heads

b)exhaust valves

c)scavenging air

d)injectors

9) The total starting air capacity required for reversible main engines is to be sufficient for a least

a)six consecutive starts

b)eight consecutive starts

c)ten consecutive starts

d)twelve consecutive starts

10) The light and medium fuels utilized in internal combustion engines provide a source of

a)lubrication for pistons and rings

b)food for microbiological organisms

c)gases most detrimental to the ozone layer of the atmosphere

d)all of the above

11) Which bearing half will receive the greatest load in a two-stroke/cycle diesel engine?

a)Lower half of the connecting rod bearing at the crankshaft end of the rod

b)Upper half of the main bearing

c)Lower half of the piston pin bearing in the connecting rod

d)All bearing halves share an equal load

12) Maximum lube system operating pressure for a diesel engine is normally regulated by a/an

a)orifice in the pump suction

b)special filter design

c)pressure drop through the filter

d)relief valve

13) A naturally aspirated diesel engine at full throttle will have an intake manifold pressure

a)slightly less than atmospheric pressure

b)approximately equal to exhaust manifold pressure at all times

c)that is widely fluctuating

d)constantly decreasing as engine load increases

14) 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

15) An increase in the air inlet manifold pressure of a diesel engine will result in a/an

a)decrease in maximum cylinder pressure

b)increase in ignition lag

c)decrease in fuel consumption per horsepower-hour

d)decrease in exhaust manifold pressure

16) Maximum lube oil system pressure is normally controlled by

a)the capacity of the lube oil pump

b)the speed of the lube oil pump

c)the outlet pressure of the lube oil pump

d)a relief valve

17) Which of the following statements is true concerning an oil cooler?

a)The oil temperature is less than the cooling water temperature

b)The oil pressure is less than the cooling water pressure

c)The oil pressure is greater than the cooling water pressure

d)The magnets are installed to remove metal particles

18) The highest pressure in any closed diesel engine freshwater cooling system is at the

a)jacket water outlet

b)expansion tank inlet

c)heat exchanger inlet

d)cooling water pump outlet

19) Concerning diesel propelled vessels, the astern power is to provide for continiuos operation astern

a)equal to that available for ahead operation

b)at 70 percent of the ahead rpm at rated speed

c)while underway and under all normal conditions

d)at 70 percent of the ahead rpm of average continious sea speed

20) Maintaining the lowest possible scavenging air temperature at all times is not recommended due to the possibility of the

a)air charge density becoming too high

b)piston crown surfaces becoming too cold

c)formation of excessive quantities of condensate

d)compression pressure being greatly reduced

21) The nuts of main bearings, connecting rod bolts and all other moving parts are to be secured by

a)hardened steel nut locks

b)cotter pins made of spring steel

c)split pins or other effective means

d)hydraulic nuts as commonly found on large low speed engines

22) If the valve tappets in a diesel engine are set at greater clearances than those specified by the engine manufacturer, those valves will

a)open late and close early

b)open late and close late

c)fail to open when the engine is cold

d)fail to open at normal operating temperature

23) Proper lubrication of the main bearings is more easily obtained in a single acting four-stroke/cycle diesel engine than a single acting two-stroke/cycle diesel engine because

a)bearing pressure in a four-stroke/cycle single acting diesel engine is continually reversed

b)bearing pressure in a two-stroke/cycle single acting diesel engine is continually reversed

c)the maximum bearing pressure is higher in a single acting two-stroke/cycle diesel engine

d)two-stroke/cycle diesel engines require more complicated lubrication piping

24) Increasing the valve clearance between a valve stem and rocker arm, will result in the valve

a)closing later

b)opening sooner

c)staying open for a shorter period of time

d)staying open for a longer period of time

25) Which of the following conditions can cause above normal air temperature to develop in the intake manifold of a four-stroke/cycle, turbocharged, diesel engine?

a)Clogged air intake filters

b)Piston blow-by

c)A defective after cooler

d)Faulty exhaust valves

26) Cooling the intake air supplied to a diesel engine will

a)reduce mean effective pressure

b)decrease average compression pressure

c)decrease air charge density

d)increase power output

27) Which of the following condition may need to be reduced when operating a large, low-speed, main propulsion, diesel engine at low loads?

a)Injection pressures

b)Control air supply pressure

c)Cooling water flow through after coolers

d)Lube oil temperature

28) One function of the fuel pump delivery check valve is to

a)prevent carbon deposits from forming on the injector nozzle

b)help the injector needle reseat without dribbling at the nozzle holes

c)provide a prolonged pressure drop in the high pressure steel piping to the injector

d)ensure a fuel leakoff between the plunger and barrel which provides lubrication for relative movement

29) A closed freshwater cooling system is commonly used with marine diesel engines because the

a)need for water treatment is eliminated

b)cooling water temperature differential is greater

c)cooling water pumps are directly reversible

d)jacket water temperature is more easily controlled

30) Fuel droplets injected into a diesel engine cylinder must have adequate penetration to

a)prolong the ignition delay period

b)ensure the beginning of fuel injection

c)thoroughly utilize the air charge

d)allow controlled fuel combustion

31) The valve cam slope angle determines the

a)engine torque characteristics

b)acceleration rate of valve opening and closing

c)engine fuel efficiency

d)diameter of intake and exhaust valves

32) The rate of fuel injection in a diesel engine cylinder depends primarily on

a)the size of the holes in the fuel nozzle

b)timing of the pump

c)supply pressure to the pump

d)shape of the combustion chamber

33) Which of the following devices is normally provided to prevent oil starvation in a diesel lubrication system utilizing the "full flow" principle?

a)Duplex strainer

b)Three-way valve

c)Pressure relief bypass line around the filter

d)Mechanical straining filter

34) A port-and-helix fuel injection pump having upper and lower plunger helixes is designed to

a)vary fuel delivery and return pressure

b)vary the beginning and ending of injection

c)operate with residual fuels only

d)provide maximum fuel delivery rate

35) One advantage of hydraulic clutches over mechanical clutches in diesel engine installations is

a)the power is transmitted at very high efficiency of 60%

b)the torsional vibrations are transmitted directly to the reduction gears

c)each clutch has a separate oil gland for reverse operation

d)no mechanical connection exists between the driving and driven elements

36) An individual injection pump is designed for variable beginning and constant ending of injection. For diesel engines operating at constant speeds, the start of injection will

a)advance as the load increases

b)retard as the load increases

c)remain unchanged regardless of load

d)always occur at top dead center

37) The amount of fuel injected in a particular time, or degree, of crankshaft rotation is termed

a)metering

b)timing

c)rate of injection

d)rate of distribution

38) In a normally operating diesel engine, the main source of lubricating oil contamination in the crankcase is a result of the

a)metal particles loosened by wear

b)air when no air cleaners are used

c)condensation of water wapors

d)breakdown of the lubricating oil itself

39) On small diesel engines, a noticeable decrease in the time interval between the replacement of the lube filter cartridge indicates

a)piston ring blow-by

b)dirty air filter

c)excessive oil pressure

d)excessive oil temperature

40) When the lower edge of the spiral begins to uncover the release port in a jerk pump, the

a)pumping continues until the plunger travels its full stroke

b)effective pumping stroke of the plunger ends

c)pressure drops slowly until the full stroke is attained

d)plunger rotates to the zero delivery position until the next stroke

41) Some diesel engines are fitted with a thermometer in the cooling water outlet from each cylinder. If the cooling water temperature from all cylinders begins to rise above normal, you should suspect

a)increased blow-by in all cylinders

b)incomplete combustion in all cylinders

c)overloading in all cylinders

d)insufficient fuel delivery to all cylinders

42) Proper operation of the main engine reduction gear set requires the operator to monitor

a)the sump oil level

b)oil flow sight glasses

c)bearing temperatures

d)all of the above

43) The duration of fuel injection developed by an individual port-and-helix fuel injection pump, is determined by the

a)total pump stroke

b)pump plunger diameter

c)plunger helix angle

d)effective pump stroke

44) Before starting a diesel engine using an attached lube oil pump, the engineer should

a)open the bypass line

b)cut in the lube oil cooler

c)pressurize the lube oil system

d)top off the expansion tank

45) A diesel engine using lube oil with too high a viscosity will exhibit

a)increased starting difficulty in cold weather

b)increased oil consumption

c)thickening at higher operating temperatures

d)minimal friction losses

46) If the main propulsion diesel engine governor works irregularly with a jerking motion, a possible cause can be

a)a sticking fuel control linkage

b)a malfunctioning overload cam

c)an unlocked overspeed trip

d)floating valves

47) During extremely cold weather, while starting an engine, it turns too slowly and fails to start. This problem is most likely the result of

a)high fuel oil viscosity

b)low fuel oil temperature

c)high lube oil viscosity

d)energized glow plugs

48) Prolonged operation of a diesel engine with a closed cooling water system, at lower than normal designed temperatures can

a)increase power output

b)decrease lube oil viscosity

c)eliminate fuel knock

d)cause sulfuric acid formation

49) Which of the listed governor characteristics will greatly affect the load sharing relationship between paralleled diesel generators?

a)Sensitivity

b)Power

c)Speed droop

d)Compensation

50) An emergency diesel generator cooling system is equipped with an automotive type thermostat. If the thermostat bellows loses its charge, the thermostat will

a)open, and the coolant temperature will increase

b)open, and the coolant temperature will decrease

c)close, and the engine coolant temperature will increase

d)close, and the coolant temperature will decrease

51) Fuel oil penetration into the cylinder of a diesel engine is

a)dependent on air turbulence

b)reduced by finer atomization

c)increased by finer atomization

d)non-existent in the precombustion chamber system

52) Precombustion chambers, air cells, and energy cells in high-speed, small bore diesel engines all serve to increase

a)firing pressure

b)ignition quality of fuel

c)fuel-air ratio during compression

d)turbulence

53). Which of the following statements best describes the operational characteristics of an isochronous governors?

a)they are suitable for use on main propulsion units

b)they strive to maintain a constant engine speed for all values of steady load

c)they cause a proportional drop in engine speed as the load is increased

d)they have poor sensitivity at high RPM.

54). Theoretical perfect combustion in a diesel engine yields by-products of

a)aldehydes and carbon dioxide

b)water vapour and carbon monoxide

c)nitrogen and carbon monoxide

d)water vapour and carbon dioxide

55) Combustion knock can occur in the cylinders of a diesel engine under any condition permitting

a)a shortened ignition delay period

b)a lean fuel/air mixture

c)excess fuel in the combustion chamber

d)rapid vaporisation of injected fuel droplets

56) When exessive fuel dilution is noted in the lube oil, the oil should be

a)centrifuged

b)filtered

c)strained

d)changed

57) Sticking of diesel engine piston compression rings may be caused by

a)high compression pressure

b)excessive ring action

c)excessive cylinder lubrication

d)improper ring rotation

58) When fuel is injected late into a diesel engine cylinder,

a)the exhaust will be clear

b)fuel consumption will be low

c)all the fuel will be burned at top dead center

d)fuel consumption will be high

59) ME LO inlet temperature should be—

a)40C

b)50C

c)60C

d)55C

60)Exhaust temp of one ME cylinder high could mean

a)fuel valves need overhaul

b)exh valve leakage

c)piston ring blow past

d)all of above

61)For a 2 stroke engine with exhaust ports—

a)scavenge ports close before exhaust ports

b)exhaust ports close before scavenge ports

c)scavenge ports and exhaust ports close at same time before BDC

d)scavenge ports and exhaust ports close at same time after BDC

62)For a 2 stroke engine with exhaust valves—

a)scavenge valve closes before exhaust ports

b)exhaust valves close before scavenge valves

c)scavenge and exhaust valves close at same time before BDC

d)scavenge and exhaust valves close at same time after BDC

63)The maximum amount of liner wear occurs at—

a)top of liner

b)1/ 3 downward from top centre

c)midway

d)bottom of liner

64)Which of the following cannot be removed from fuel oil by centrifuging in the purifier and micro-filtration

a)sodium

b)aluminium and silicon

c)vanadium

d)ash

65)In the preheater before purifier the recommended heavy oil preheat is-

a)85c

b)98C

c)110C

d)120c

66)For a ME which has a 5 micron fuel filter, a homogenizer ( omega fire ) is usually fitted –

a)before the purifier

b)after the purifier

c)after the 5 micron filter to ME

d)before the horizontal clarifier

67)For a main engine fuel system which has a 5 micron filter ,a super decanter is usually fitted--

a)before the purifier

b)after the purifier

c)after the 5 micron filter to ME

d)before the horizontal clarifier

68)For low sulphur 380 cst fuels the TBN of MECC oil should be in the region of—

a)20

b)40

c)60

d)70

69)Using a MECC oil of high BN can cause—

a)improper centrifuging of water

b)Calcium laquer deposits on bearings

c)sludge formation with water in ME sump

d)all of above

70)When using a high BN MECYL oil and suddenly the ship has to use low sulphur 380 cst HO in the ME, due to SECA area entry--

a)reduce the feed of MECYL

b)increase the feed of MECYL

c)do not change the feed rate

d)increase the BN of the MECYL

71)ME scavenge air temperature is adjusted by

a)controlling the sea water inlet

b)controlling the sea water outlet

c)keeping outlet valve 100% open always.

d)none of above

72)The ME jacket FW cooling outlet temperature is-

a)80C

b)95C

c)50C

d)55C

73)The scavenge air high temperature set point for 2 stroke ME is

a)40C

b)55C

c)65C

d)35C

74)You see white smoke coming from the ME funnel stack, this could be

a)one or more cylinders not getting enough fuel

b)too low compression pressure

c)water in fuel

d)all of above

75)The crank angles of a 2 stroke engine are—

a)2 cylinder engine/ 90 degrees

b)4 cylinder engine/ 60 degrees

c)6 cylinder engine/ 90 degrees

d)4 cylinder engine/ 90 degrees

76)Crankcase explosions of main engines can be due to-

a)over heating of MECC oil

b)poor condition of liners/ rings

c)crankshaft / thrust bearing failure

d) all of above

77)If there is air in the fuel oil filter, the compression and reexpansion of air will—

a)not allow the fuel injection valve to close

b)not allow the fuel injection valve to open

c)makes no difference

d)none of the above

78) Which of the bearings listed are most widely used for the main and connected rod bearings of a diesel engine?

a)roller

b)sleeve

c)precision insert

d)needle

79) Which of the following methods is normally used to lubricate bearings in a small high-speed diesel engine?

a)splash lubrication

b)pressure lubrication

c)sight feed lubricators

d)mechanical lubricators

80) 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

81) In a bypass 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, reheater, and returns to the sump

82) In a diesel engine, the main bearings are used between the

a)connecting rod and the crankshaft

b)wrist pin and the connecting rod

c)camshaft and the engine block

d)crankshaft and the engine block

83) Heat exchangers are most commonly found in a small auxiliary diesel engine

a)fuel oil system

b)governing system

c)air starting system

d)lube oil system

84) Multiple concentric valve springs are often used with diesel engine valves to

a)enable research and development of cam contour to be simplified

b)operate the valve gear where the larger force is required, but space limitations restrict use of a large spring

c)allow for easier valve replacement

d)enable a total smaller valve spring force to keep the valve tight on its seat

85) Which of the listed bearing installations is subjected to swinging motion?

a)crankshaft journal

b)crankpin bearings

c)wrist pin bearings

d)thrust bearings

86) One advantage of vacuum feed type cylinder lubricators over the liquid sight type is

a)there are fewer moving parts

b)adjustment is not required

c)better metering accuracy

d)a lower grade of oil may be used

87) Cooling water pumps driven by direct reversing diesel engines are usually of the straight impeller vane type -pump with a concentric housing to

a)provide cooling water flow when the engine is running either ahead or astern

b)provide the greatest pump efficiency

c)prevent pump clogging from marine growth

d)prevent cavitation at the pump outlet

88) Motor vessels usually have an independent lube oil system each for the main engine and main reduction gears because

a)coolers are not needed for the gear system

b)contaminants produced by the engine could harm the reduction gears

c)non additive oils are used in the main engine system

d)different type centrifuges are required for the main engine and reduction gear lube systems

89) 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

90) 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

91) Diesel engine main and connecting rod precision bearings are made in halves. Each half exceeds one-half the bearing circumference by a small amount. The small amount is termed

a)clearance

b)crush

c)pitch

d)thrust

92) The piston rod scraper box incorporated in a single acting two-stroke/cycle, crosshead diesel engine serves to

a)eliminate the necessity for an oil scraper ring

b)prevent side thrust and cylinder scoring

c)prevent sludge and dirty oil from entering the crankcase

d)scrape oil and carbon deposits off the cylinder walls

93) The proper location for journal bearing oil grooves is

a)in the region of the load bearing surface

b)as a side relief where the two shells meet

c)at the bottom of the bearing

d)halfway between bottom and where shells meet

94) How are hydraulic valve lash adjusters on diesel engine rocker arm assemblies lubricated?

a)Cup-fed grease

b)Sealed self-lubricators

c)Metered hydraulic oil supply

d)Forced lube oil supply

95) Main propulsion diesel engines having a bore exceeding 300 mm are to have at least

a)two independent means of starting the engine

b)five air starting valves to permit the admission of starting air at any crank angle

c)one (explosion relief) valve at the position of each main crank throw

d)two engine driven lube oil pumps capable of parallel operation

96) Integral water jacket liners use O-rings near the bottom of the liner, these O-rings serve to

a)form a water seal between the liner and engine block

b)allow for slight misalignment of the liner

c)prevent the escape of lubricating oil from the crankcase

d)ensure proper temperature flow between the liner and engine block

97) 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

98) A characteristic of a bearing material which permits small dirt particles to become embedded in the surface and is

a)desirable, as it will prevent damage to the journal surface

b)desirable, as it will assist in keeping the lube oil filters clean

c)undesirable, since the embedded particles will score the journal

d)undesirable, since the particles will interfere with lube oil flow

99) 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

100) Which of the following devices controls the discharge flow rate of an attached, positive displacement, rotary gear, diesel engine, lube oil pump?

a)A pressure regulating valve

b)A pressure relief valve

c)The engine speed

d)An orifice

101) The expansion tank for a diesel engine closed cooling system is designed to maintain a constant head on the system and

a)reduce water temperature

b)reduce water turbulence

c)provide an air cushion

d)allow for an increase in water volume as the engine warms up

102) To minimize corrosion, fuel oil strainer disks, spacers and scraper blades are made of

a)brass

b)copper

c)iron

d)monel metal or stainless steel

103) Which of the following statements describes the function of an expansion tank in a diesel engine cooling system?

a)Maintains a constant head on the system

b)Reduces the air cock when fires are lighted

c)Provides a low pressure point for the addition of makeup cooling water

d)All of the above

104) On a large diesel engine installation, crankshaft axial alignment is maintained by the

a)piston rod guides

b)engine thrust bearing

c)crosshead bearing

d)main shaft flexible coupling

105) Scavenging in a four-stroke/cycle diesel engine occurs during the

a)last part of the exhaust stroke, and the first part of the intake stroke

b)last part of the intake stroke only

c)early part of the injection stroke only

d)early part of the power stroke

106) In a large, slow-speed, main propulsion diesel engine, which of the parts listed is under tension when the engine is running?

a)Bed plate

b)Column

c)Entablature

d)Tie rod

107) The lube oil cooler is located after the lube oil filter in order for

a)the filter to operate more efficiently

b)the lube oil cooler to be bypassed

c)positive lube oil pump suction to be assured

d)galvanic action in the cooler to be minimized

108) In two-stroke/cycle diesel engine, the process of scavenging begins as the

a)piston nears and passes TDC

b)early part of the upstroke

c)piston passes BDC

d)early part of the downstroke

109) With respect to the flow of lubricating oil through a diesel engine, the lube oil coolers are located after filters in order to

a)allow filtration of less viscous oil

b)decrease the pressure drop across the filter

c)improve overall filtration

d)all of the above

110) Passages are drilled in the crankshafts of diesel engines to provide lubricating oil to the

a)main bearings

b)connecting rod bearings

c)piston pin bushings

d)All of the above

111) The outlet from an expansion tank of a closed freshwater cooling system should be piped to the

a)cylinder head water outlet header

b)cylinder jacket inlet main

c)heat exchanger inlet connection

d)jacket water pump suction line

112) The intake valves in diesel engine are reseated by

a)cam followers

b)push rods

c)combustion gases

d)valve springs

113) Small amounts of moisture are necessary to trigger the growth of microbiological organisms found in some marine fuels. Some sources of water contamination are

a)tank surface leakage

b)humidity and condensation

c)improper tank washing procedures

d)All of the above

114) 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

115) On most modern diesel engines,the main and connecting rod bearings receive their lubricating oil by

a)banjo feed

b)splash feed

c)gravity feed

d)pressure feed

116) A unit type fuel injector is used on a diesel engine to

a)meter the fuel

b)produce the proper fuel oil pressure

c)atomize the fuel

d)all of the above

117) Lubricating system for diesel engines are usually designed to initially provide lube oil to the engine

a)camshaft bearings

b)main bearings

c)piston crowns

d)cylinder walls

118) Mechanical lubricators for diesel engine cylinders are usually small reciprocating pumps which are

a)operated manually once each hour

b)operated until the engine has started

c)placed into operation only at maximum load

d)adjustable to meet lubrication requirements

119) Shacker, circulation, and spray are the three general methods used in

a)pre-injection fuel oil treatment

b)lube oil filtration

c)fuel oil purification

d)piston cooling

120) Fuel injector nozzles are usually of the multi-orifice type with the number and placement of the holes arranged according to the

a)type of piston rings

b)pressure of the fuel system

c)size of the pump plunger spring

d)design of the combustion chamber

121) What is the crank angle between any two crank throws in the firing order of a four-stroke/cycle, in line, eight cylinder diesel engine?

a)45°

b)60°

c)90°

d)100°

122) The main reason counterweights are added to crankshafts is to

a)reduce piston side thrust

b)reduce crankshaft end thrust

c)provide uniform loading and wear of main bearings

d)increase the strength of the crank webs

123) A viscous damper, as used on a marine diesel, is a sealed precision built device which dampens the torsional vibrations in the

a)camshaft

b)flywheel

c)crankshaft

d)thrust shaft

124) A crankshaft whose center of gravity coincides with its center line is said to be

a)dynamically balanced

b)statically balanced

c)counter balanced

d)resonantly balanced

125) The possibility of damage from operating a diesel engine at critical speeds is reduced by the use of

a)an isochronous governor

b)elastic engine mounts

c)a vibration damper

d)a cast iron bed plate with good flexible qualities

126). In a diesel engine lube oil system, which of the following parts should be lubricated first?

a)Camshaft bearings

b)Main bearings

c)Piston crowns

d)Cylinder walls

127) When fuel oil heaters are required for engine operation,

a)each heater shall have the capacity to supply the main engine at full power

b)at least two heaters of approximately equal size are to be installed

c)the system shall be designed to permit series or parallel operation

d)none of the above

128) An advantage of aluminium pistons compared to cast iron pistons is:

a)greater high temperature strength

b)better heat conductivity

c)greater weight per cubic cm

d)increased resistance to wear

129) Which engine component increases air density and helps to improve engine operating efficiency?

a)impeller

b)compressor

c)aftercooler

d)exhaust diffuser

130) An electric heater built into the cylinder water jacket would be used to

a)raise lube oil viscosity for easier starting in cold weather

b)increase air inlet temperature

c)increase compression ratio

d)increase water temperature for easier starting in cold weather

131) Which is found with both mechanical and hydraulic governors?

a)direct linkage between the ball head and fuel rack

b)a servomotor

c)a compensating device

d)flyweights

132) Which of the following design features will reduce the possibility of overheating the top compression rings of a cast iron piston?

a)The top ring is located as close to the piston as possible

b)The inside surface of the piston head is rounded into the ring belt

c)A nickel-bearing insert is cast into the top ring groove

d)A heat dam design is sometimes used in the piston head

133) The purpose of heat dam used in some diesel engine cast iron pistons is to

a)concentrate all heat in the piston crown

b)increase the distance of travel for heat from the crown to the top ring groove

c)ensure that all heat in the piston crowns is conducted to the top ring

d)provide a short direct path for heat to flow from the crown to the top ring

134) Valves used in diesel engine fuel oil pressure piping are to be

a)installed to close against flow

b)solenoid released upon the failure of engine lubrication

c)either of the gate or globe valve type

d)forge constructed under the approval of the Marine Inspector

135). Cast iron pistons used in large propulsion engines are constructed with

a)no taper whatsoever

b)the skirt being tapered and smaller than the crown

c)the skirt being tapered and larger than the crown

d)the crown being tapered and smaller than the skirt

136) The diameter of a piston is usually less at the crown than at the skirt, in order to

a)facilitate the installation of piston rings

b)allow for the expansion of the piston during operation

c)prevent crankcase vapors from entering the combustion chamber

d)reduce wearing of the upper cylinder liner

137). Which of the following manufacturing methods is recommended for diesel engine fuel injection line piping?

a)Cold rolled

b)Electric resistance welded

c)Seamless drawn

d)Straight seam

138) Exhaust pipes of multiple engine installations are not to be interconnected, but are to be run separately to the atmosphere

a)unless arranged to prevent the return of gases to an idle engine

b)to a point not lower than the highest load line

c)at a location segregated from other ventilation systems

d)and shall be protected by a rain guard or similar device

139) Which of the bearing types listed is most commonly used in smaller vessel main propulsion reduction gears as thrust bearings?

a)ball bearings

b)poured bearings

c)sleeved bearings

d)tapered roller bearings

140) The main reason for using bimetallic piston rings is to

a)increase engine thermal efficiency

b)reduce specific fuel consumption

c)reduce the probability of ring fracture

d)allow for ring expansion

141) A spring-loaded centrifugal flyweight governor responds to reduced engine load with an immediate increase in

a)pilot valve oil pressure

b)speeder spring force

c)compensation needle valve clearance

d)centrifugal force on the flyweights

142) The reason why the pneumatic reversible roller guide of fuel pump could oscillate is

a)incorrect clearance in the air cylinder guideway/ reverse arm bushing

b)too large air pressure drop

c)insufficient air supply

d)all of above

143) Reasons for exhaust valve hammering could be-

a)deficiency in oil supply

b)errors in air spring

c)excessive leakage in the HP oil system

d)all of above

144) error in the air spring system causing exhaust valve hammer can be due to—

a)air pressure too high

b)maladjusted safety/ drain valve

c)supply pressure not corresponding with safety valve opening pressure

d)all of above

145)deficiency in oil supply causing exhaust valve hammering can be due to-

a)foaming oil due to air leak at pump suction

b)too low oil supply pressure

c)too high oil temperature (MECC ) causing low viscocity

d)all of above

146) excessive difference between combustion pressure and compression pressure in a ME cylinder can be due to

a)low scavenge air pressure

b)change in exhaust valve timing

c)burnt exhaust valves

d)all of above

147)the difference between water washing and dry cleaning the TC turbine is

a)there is no difference one is wet, the other is dry

b)wet washing requires reduced load

c)dry cleaning requires reduced load

d)none of the above

148) oscillations of pneumatic reversible roller guide for fuel pump can cause-

a)mechanical damage to air cylinder

b)leakages on manoevering air

c)loss of engine manoeveribility

d)all of above

149) During manoevering the MECYL feed rate is usually

a)125% of service feed rate

b)50%

c)200%

d)300%

150)The difference between the max combustion pressure and compression pressure in a 2 stroke engine cylinder unit is

a)40 bars

b)10 bars

c)70 bars

d)65 bars

151) The air spring pressure to prevent ME exhaust valve hammer is in the region of—

a)2 kg

b)7kg

c)12 kg

d)14 kg

152.Your indicator diagram from one of the main engine cylinders is shown. P Comp normal, P Max is low--What kind of steps do you think is necessary to rectify the failure?

A Check fuel injector valve, fuel injection timing, fuel pump suction valve and fuel pump lead

B Clean air cooler and turbocharger air cooler

C Adjust fuel pump lead only during operation

D Increase fuel pump setting.

153.Your indicator diagram is as shown. What kind of steps do you think are necessary to rectify the failure? Pc normal pm high

A Check if fuel injection is too early or fuel pump lead too large

B Check if fuel injection valve is correctly by adjusted.

C Check that you have correctly viscosity/fuel preheating.

D Replace the fuel valve.

154.A drawn indicator diagram from one of the main engine cylinders is as shown. What kind of steps are necessary to rectify the failure?—pc and pm both low

A Overhaul the unit to determine faults such as: piston ring blow-by, exhaust valve malfunction, clogged scavenging ports, delayed ignition etc.

B Adjust fuel pump lead to inject more fuel so as to maintain power balance

C Change fuel injection valve

D Check fuel pump safety valve.

155.During inspection of piston and liners through scavenging ports, piston rings on all units were found as shown (micro seizure). The best way to stop its progress is:

A Increase cylinder oil consumption, determine fuel quality and readjust the fuel oil purifiers

B Increase cylinder oil consumption

C Replace all piston rings

D Run engine at lower load.

156.During inspection and calibration of one unit, you observe the situation shown. The conclusion is clover leafing. The main engine uses high grade TBN cylinder oil. What do you have to do in order to reduce wear?—depression on either side of all lub orifices—like 10 paise coin

A Decrease jacket cooling water temperature to avoid heat stress

B Increase the jacket cooling water temperature to avoid the sulphur dew point

C Increase cylinder oil consumption to neutralize the sulphur

D Contact engine maker for advice.

157.Your vessel is entering a tropical area and high humidity is expected. To avoid condensation in the main engine's air cooler, it is recommended to:

A Operate the engine with slightly open drain cocks, scavenging to get rid of the water

B Reduce speed.

C Decrease the air temperature so proper draining can be achieved from the air cooler

D Increase scavenging air temperature to above dew point

158.During inspection of the crank bearing for one of the units in the main engine, the bearing shell was found as follows: Surface of the white metal was black and very hard. Patches of black incrustations have worn grooves in the journal. What was the cause?

A Dirt in the lubricating oil

B Wrong casting of bearing shell

C Water in the lubricating oil during service

D Bearing shell service time exceeded.

159.When carrying out piston overhaul, it is important to clean the ring grooves properly. Why?

A To make sure gas pressure can enter freely on top of and behind the piston ring

B To make the rings fit in the groove

C All rings must be changed to maintain a perfect sealing

D That piston rings can move freely in the grooves.

160.During operation of the main engine, the exhaust temperature increases on one of the cylinders. The turbocharger starts surging and smoke from the turbocharger inlet air filter occurs. What is the probable cause?

A High back pressure in the exhaust system

B Turbocharger failure

C Fuel valve stick in open position.

D Scavenge box fire

161.You are having a blow-by on the main engine, but due to the circumstances, it is impossible to stop and do a piston overhaul. What is the correct action to take?

A Reduce speed.

B No action necessary.

C Reduce speed temporarily and increase cylinder oil consumption.

D Increase cylinder oil consumption.

162.You have installed a new bearing in the main engine. What is the necessary action to take in the running-in period?

A Stop after 30 min. running to hand feel the bearing.

B Allowance must be made for a running-in period with reduced speed and careful temperature monitoring.

C No necessary steps to be taken.

D Allow for 1 hr. running with appropriate temperature monitoring of the bearing.

163.You are experiencing large hunting on the fresh water cooling system. What is the reason?

A The fresh water circulating pump is worn out.

B The cooling water temperature is too low.

C You have a cracked liner, or cover.

D The expansion tank is empty.

164.Why is it important to check the timing on the cylinder oil lubricators?

A To avoid high temperature in the combustion chamber.

B To get the right amount of oil into the cylinder.

C To get the oil into the cylinder when the piston is in the right position

D To avoid excess lubrication.

165.Why do we use cylinder oil?

A To neutralize the sulphur and get a lubricating oil film between piston rings and liner.

B To get a lubricating oil film between piston rings and liner.

C To neutralize the sulphur in the fuel.

D To avoid blowby.

166.How large a deviation in opening pressure can be accepted in a diesel engine injection valve?

A 15 kg/cm2

B 40 kg

C 50 kg

D 70 kg

167.What will the effect be, if you have a fuel injector valve that is dripping after the injection is finished ?

A Less carbonizing.

B Damage to piston and liner.

C Greater output of the engine.

D Better combustion.

168.How is the quantity of fuel oil, in HP fuel oil pump adjusted when the engine is running ?

A By adjustment of the pressure valve in the pump.

B By adjusting the length of the pump stroke.

C Turning the plunger piston according to engine load

D Adjusting oil flow to the HP fuel oil pump.

169.When a changeover from HFO to diesel oil is going to take place, we want this to be carried out as follows

A as fast as possible to save HFO.

B as fast as possible to save steam.

C as quick as possible, to obtain a fast temperature reduction to cool the HP fuelpumps.

D slow to get slow cooling.

170.If you are going to enter the engines crankcase (go inside), how will you secure the engine after you have closed the main starting air valve ?

A Engage the turning gear on the engine.

B Close absolutely all valves on the starting air bottle.

C Close the instrument air supply.

D Keep a man posted in the control room to watch that nobody tries to start the engine

171.If you get a heavy scavenging air fire, which one of the following part is likely to take the most serious damage ?

A Stuffing box.

B Exhaust valve.

C Piston.

D Crosshead bearing.

172.Why are we blowing the engine before start (slow turning on air) ?

A To be sure that we do not have water collected in the cylinders.

B To be sure that no parts are loose, or that the engine is blocked from rotation.

C To get fresh air into cylinders ensuring a safe start of the engine.

D To be sure that all indicator cocks are closed, and no passage into the combustion chamber.

173.The cylinder oil for FO with high sulphur content is supposed to be:

A acidic.

B Alkaline

C neutral.

D does not matter.

174.A 2 stroke engine is usually equipped with an auxiliary blower fan, which is supposed to be used:

A continuously, together with the turbochargers to ensure enough air to the engine during full speed running.

B during continuously reduced speed under a longer sea voyage.

C during manoeuvre and manoeuvre speed condition (arrival and departure)

D during a scavenging fire, to help put out the fire.

175.What do you consider as the most important task after a piston job ?

A A search inside the crankcase for tools and rags.

B Starting the auxillary blower to ventilate the scavenging belt, and the cylinder liners, to ensure that the engine has sufficient fresh air for starting.

C Patch up destroyed paint work on the crankcase doors.

D Starting the engine to see that it rotates

176.Why is it so important to keep the lub oil viscosity within safe limits?

A To keep the oil protective film between moving metal surfaces .

B The luboil viscosity has no influence on the oil's lubrication ability.

C To keep the additives in good condition.

D It is not important

177.Total Base Number ( TBN ) is important as a measure of neutralizing ability against strong Acids. What will You do if this TBN base number is reduced to a low level?

A Renew lub oil in the system.

B Send one lub oil sample to new analysis.

C Nothing.

D Purify the oil system.

178.What can happen with a lub. oil cooled piston if you stop the lub. oil pump immediately after You stop the engine?

A Nothing happens.

B The oil flashpoint will be changed.

C Overheating of the piston, and oil coke deposits in the cooling chambers

D You save the oil sealings in the piston.

179.You have checked the oil viscosity in an auxiliary engine with the viscosity test kit. The result shows that the viscosity is high. What will you do?

A Decrease the cooling water temperature for the oil.

B Clean the system and change the oil

C Increase the cooling water temperature for the oil.

D Increase the lub oil pressure.

180.You have checked the oil viscosity in an auxiliary engine with the viscosity test kit. The result shows that the viscosity is low. What will you do?

A Clean the system and change the oil.

B Increase the oil temperature.

C Start to purify the oil.

D Decrease the oil temperature.

181.What could be the reason if the lub oil viscosity increase?

A Heavy fuel oil leakage to the lub oil system.

B The lub oil viscosity will not increase.

C Water-leakage to the lub oil system

D High lub oil temperature.

182.What could be the reason if the lub oil viscosity decrease?

A Heavy fuel oil leakage to the lub oil system.

B Diesel oil leakage to the lub oil system

C Low lub oil temperature.

D Wrong lub oil pressure

183.A water content greater than 2 % is detected in a lub oil system. What is the best action to do?

A Continuous purifying the system with the lub oil pumps running.

B Boil out the water by increasing the temperature.

C Segregate the oil in a seperate tank for continuous purifying.

D It is no danger before the water level reach 6-8%.

184.What long term effect will excessively high temperature have on lubricating oil quality?

A Cause oxidation which reduce viscosity.

B Evaporates the oil giving high consumption.

C The oil flashpoint will be changed.

D Cause oxidation which increase viscosity.

185.Which would be the most suitable place to obtain an oil sample for analysis?

A From the lub. oil pump suction line.

B From the system pipeline

C From the oil cooler drain.

D From the filter drain.

186.If water contamination occurs in the crankcase oil of an auxiliary engine the oil viscosity will:

A Increase.

B Nothing happens.

C Stay at the same.

D Decrease.

187.What type of lubricating oils are generally used in auxiliary engines?

A Detergent.

B Alkaline.

C Synthetic.

D It is not important.

188.In a Burmeister & Wain main engine, at what point is cylinder oil injected?

A Just before "Top Dead Centre".

B As the piston passes "The Lubrication Points" in a downward direction

C As the piston passes "The Lubrication Points" in an upward direction

D Just before "Bottom Dead Centre"

189.What differential pressure would you expect to find across an engine lub.oil filter?

A 1.2 Bar

B 3.0 Bar

C Zero

D 0.2 Bar

190.You notice the sump level in an engine has increased and no new oil has been added. What action would you take?

A Drain some oil from the engine.

B Stop the engine and look for a fuel or water leak.

C Reduced the load, and look after fuel or water leak.

D Leave it the same.

191.Oil analysis results show a high level of tin. What could be the cause of this?

A Bearing damage.

B Water contamination.

C Fuel contamination

D Too high lub.oil temperature.

192.We have two kinds of turbocharging systems: constant pressure and impulse. The difference between these two can be found in:

A The exhaust gas receiver.

B Scavenging air coolers.

C The blades on the exhaust gas turbine.

D The scavenging valves of the engine.

193.We have a problem with surging in the turbocharger. Which of the following could be the cause?

A Worn out bearings on the turbocharger.

B The lubrication oil pump is malfunctioning.

C Dirty rotor blades.

D Dirty scavenging air cooler on the air side.

194.The revolutions on the turbocharger have increased during the night with unmanned engine. Could this be caused by:

A The viscosity of the fuel is to high.

B We have favourable winds and current.

C The current and wind are holding the vessel back

D Poor combustion due to malfunction of fuel valves

195.The turbocharger (constant pressure) is making "whoofing" noises. What might be the cause?

A Heavy seas from behind.

B A faulty turbocharger bearing.

C One or more leaking exhaust-valve(s).

D Strong current against

196.After how many hours would you consider changing the turbocharger bearings, even though all appears to be normal?

A 12.000 hours.

B 4.000 hours.

C 25.000 hours.

D 30.000 hours.

197.The timing of the engine is delayed. The exhaust temperatures are high. How would you expect this to affect the turbocharger?

A Decreased turbocharger revolutions.

B Surging of the turbocharger.

C Increased turbocharger revolutions

D Higher air and gas temperature after turbocharger.

198.We have a problem with vibration in the turbocharger. What might be the cause?

A Dirty air inlet filter.

B The turbine rotor is not balanced

C The lubricating oil needs to be changed.

D Worn out turbocharger bearings.

199.With full load on the main engine, the RPM for the turbocharger is too low. What may cause this?

A The diffuser ring is damaged.

B Exhaust temperatures on the main engine are too high.

C Dirty nozzle ring.

D The lubricating oil pump is malfunctioning.

200.With full load on the main engine, the turbocharger tachometer reads: Too low RPM. Why?

A Damaged connection between pick-up and tachometer unit

B Pick up is not connected to turbocharger.

C Turbocharger need to be cleaned/overhauled.

D Pick up for tachometer is wrongly adjusted.

201.The lubricating oil on the exhaust side of the turbine blower gets very dirty after only a few hours in service. What can the reason be?

A Exhaust gas leaking into the oil chamber.

B Wrong type of oil used.

C Lubricating oil is mixed with salt water

D Worn out bearing turbine side

202.After water-washing the turbocharger exhaust side, the blower starts to vibrate. What has happened?

A Water drain for washing system is clogged.

B Foundation bolts for the blower unit are loose

C The rotor blades are damaged or the blades are not properly cleaned

D Inlet filter partly clogged.

203.The blower's air delivery is not sufficient. What is the cause?

A Air temperature in engine room too high.

B Dirty scavenge duct.

C Clogged air inlet filter.

D Cooling water temperature too high

204.Why is it important to slow down the main engine RPM while water-washing the turbocharger?

A To protect the bearings.

B To protect the exhaustgas economizer.

C To protect the blower side.

D Not to damage the rotor blades.

205.Some engine manufacturers recommend that washing of the compressor side is not carried out. Is this due to:

A Greasy sludge from the compressor sticking between the fins in the air coolers, necessitating extra cleaning of these.

B Large volumes of water being carried over into the cylinders of the engine.

C The nozzle ring becoming corroded

D The thermal shock exhibited by the vanes.

206.What is the meaning of the term "valve clearance"?

A The clearance between the rocker arm and valve pushrod.

B The clearance between valve spindle disc and seat.

C The clearance between the rocker arm and camshaft pushrod.

D The clearance between the rocker arm and valve pushrod in either warm or cold state.

207.The meaning of lapping a valve and valve seat is:.

A Adjust the overlapping of the inlet and exhaust valves.

B Grind the valve against the valve seat to obtain a uniform sealing surface.

C Machining the valve in a lathe machine.

D Repair by welding.

208.Some 4-stroke engines are fitted with a rotorcap on the cylinder head valves. For what reason?

A Rotate the inlet valve during operation.

B Distribute the exhaust gas or the air inlet better to improve combustion.

C Improve the scaling surface function, increase the service time of the exhaust valve in the engine

D To prevent the valve spindle from sticking..

209.When overhauling the cylinder covers on a modern 4-stroke engine, is it important not to interchange inlet and exhaust valves?

A Not so important.

B Important due to different material and working conditions.

C Can be changed if same size.

D Important due to different type size valve guide.

210.What is the purpose of the cylinder head safety valve?

A To relieve excessive high pressure in the cylinder to protect the engine from being damaged.

B To adjust the cylinder pressure to a safe working pressure.

C A valve for safety stop (emergency) of the engine.

D For indication of engine being overloaded.

211.Most of the engine makers recommend to change the cylinder head gaskets each time a piston overhaul is carried out. Why?

A To obtain a proper sealing and correct distance between piston and cover in TDC position.

B To increase the consumption of parts so they can make more money.

C To avoid heat transfer to the cylinder head.

D To be granted a proper sealing with a new gasket.

212.Some 4-stroke engines are equipped with cooled fuel valves. Why is it so important to keep the coolant's temperature correct?

A For cooling only.

B For preheating only

C To avoid overheating the fuel nozzle

D For cooling and to maintain correct viscosity on the fuel when injectedMAIN ENGINE ANSWERS

1-B

2-B

3-D

4-A

5-A

6-B

7-D

8-C

9-D

10-B

11-C

12-D

13-A

14-A

15-C

16-D

17-C

18-D

19-B

20-C

21-C

22-A

23-A

24-C

25-C

26-D

27--C

28-B

29-D

30-C

31-B

32-A

33-C

34-B

35-D

36-A

37-C

38-D

39-A

40-B

41-C

42-D

43-D

44-C

45-A

46-A

47-C

48-D

49-C

50-C

51-B

52-D

53-B

54-D

55-C

56-D

57-C

58-D

59-A

60-D

61-A

62-B

63-B

64-C

65-B

66-B

67-A

68-A

69-D

70-A

71-B

72-A

73-B

74-C

75-D

76-D

77-B

78-C

79-B

80-B

81-C

82-D

83-D

84-B

85-C

86-C

87-A

88-B

89-D

90-B

91-B

92-C

93-B

94-D

95-C

96-C

97-C

98-A

99-A

100-C

101-D

102-D

103-D

104-B

105-A

106-D

107-A

108-B

109-D

110-D

111-D

112-D

113-D

114-B

115-D

116-D

117-B

118-D

119-D

120-D

121-C

122-C

123-C

124-B

125-C

126-B

127-B

128-B

129-C

130-D

131-D

132-D

133-B

134-A

135-D

136-B

137-C

138-A

139-D

140-C

141-D

142-D

143-D

144-D

145-D

146-D

147-B

148-D

149-A

150-A

151-B

152-A

153A

154A

155A

156B

157D

158C

159A

160D

161C

162B

163C

164C

165A

166A

167B

168C

169D

170A

171A

172A

173B

174C

175A

176A

177A

178C

179B

180A

181A

182B

183C

184D

185B

186A

187A

188C

189D

190B

191A

192A

193D

194C

195A

196A

197C

198B

199A

200D

201A

202C

203C

204D

205A

206A

207B

208C

209B

210A

211A

212D

1) A semiconductor that decreases resistance with an increase in temperature is known as a

a)resistor

b)thermistor

c)diode

d)thermopile

2) Brushless generators are designed to operate without the use of

a)brushes

b)slip rings

c)commutators

d)all of the above

3) A ground can be defined as an electrical connection between the wiring of a motor and its

a)shunt field

b)circuit breaker

c)metal framework

d)interpole

4) Which of the following statements represents the main difference between a relay and a contactor?

a)Contactors control current, relays control voltage.

b)A relay is series connected and contactor is parallel connected.

c)Contactors can handle heavier loads than relays.

d)Contactors are made from silver and relays are made from copper.

5) The electrolyte used in a nickel-cadmium battery is distilled water and

a)diluted sulfuric acid

b)potassium hydroxide

c)lead sulfate

d)zinc oxide

6) A resistance in a circuit of unknown value is to be tested using the voltmeter/ammeter method. Therefore, the meters should be connected with

a)both meters in series with the resistance

b)both meters in parallel with the resistance

c)the ammeter in series and the voltmeter in parallel with the resistance

d)the ammeter in parallel and the voltmeter in series with the resistance

7) One factor that determines the frequency of an alternator is the

a)number of turns of wire in the armature coil

b)number of magnetic poles

c)strength of the magnets used

d)output voltage

8) The number of cells in a 12 volt lead-acid battery is

a)three cells

b)four cells

c)six cells

d)twelve cells

9) A delayed-action fuse is most frequently used in which of the listed circuits?

a)lighting circuit

b)motor circuit

c)electric heater circuit

d)radar circuit

10) The freezing point of the electrolyte in a fully charged lead-acid battery will be

a)higher than in a discharged battery

b)lower than in a discharged battery

c)the same as in a discharged battery

d)higher than in a discharged battery, but the specific gravity will be less

11) Fuses are rated in

a)voltage

b)amperage

c)interrupting capacity

d)all of the above

12) Power transformers are rated in

a)kilowatts

b)ampere-turns

c)kilowatt-volts

d)kilovolt-amperes

13) Which of the following devices will prevent a DC generator from becoming motorized?

a)overcurrent relay

b)motorization trip

c)reverse power relay

d)reverse current relay

14) A three-phase induction-type motor experiences an open in one phase. Which of the listed automatic protective devices will prevent the machine from being damaged?

a)overspeed trip

b)thermal overload relay

c)three-pole safety switch

d)magnetic blowout coil

15) Across-the-line starters are used with AC motors to provide

a)reduced starting current

b)regulated starting current

c)high starting torque

d)controled starting acceleration

16) In testing a three-phase delta winding for an open circuit using a megger, you must

a)test each phase with all connections intact

b)measure the voltage across the open connections while testing

c)test the windings as parallel groups to avoid short circuiting

d)open the delta-connctions to avoid shunting the phase being tested

17) Mercury filled thermometers should never be used to determine the temperature of the battery electrolyte because accidental breakage of the thermometer can cause

a)severe sparking and explosions

b)rapid oxidation of battery plates

c)contamination of the electrolyte

d)corrosion on the battery terminals

18) The purpose of a main switchboard circuit breaker's reverse-power trip is to

a)prevent main circuit overload

b)protect the circuit breaker blowout coil

c)prevent alternator motorization

d)prevent low voltage tripout

19) Regarding an induction motor, the power developed by the rotor automatically adjusts itself to

a)power required to drive the load

b)speed required to drive the load

c)current flow in the motor stator

d)torque developed by the rotating field

20)The purpose of a magnetic relay is to

a)open a circuit only in the event of overload

b)remotely open and close contacts

c)provide overcurrent protection during starting

d)relay voltages at increased power

21) A semiconductor is a material with a

a)conductivity higher then a normal conductor

b)conductivity higher then a normal insulator

c)high conductivity at low temperatures

d)low conductivity at high temperatures

22) The charge of an alkaline battery is determined with a—

a)hydrometer

b)ammeter

c)voltmeter

d)hygrometer

23)The advantage of an alkali battery over a lead acid battery is—

a)it has no electrolyte loss.

b)it maintains a max voltage of 1.75

c)it has a longer life

d)all of above

24) If the pointer fails to come back to zero when the megger is not in use it means—

a)the megger is out of calibration

b)this is normal

c)the hairsprings are burnt out

d)the pointer is stuck

25) the power factor of an induction motor operating at full load is-

a)leading

b)lagging

c)unity

d)no change

26) In a 3 phase delta connection, the line current will be the product of phase current and

a)1.501

b)2.216

c)1.414

d)1.732

27) The principal difference between a 3 phase squirrel cage induction motor and a single phase induction motor is-

a)one is a split phase motor using a capacitor, while the other uses an inductor

b)one has a revolving field which drags the rotor slightly behind it, while the other runs in step.

c)there is no difference

d)one needs DC excitation, the other need no excitation

28) Which of the following devices are used for protection of AC propulsion motors and generators?

a)jamming relays

b)low voltage release

c)timing relays

d)phase balance relays

29) 2 alternators are operating in parallel. If there is an increase in load and decrease in voltage, the AVR will

a)cut out the field resistance

b)cut in the field resistance

c)cut in armature resistance

d)cut out armature resistance

30) A galvanometer is used to measure-

a)small voltages

b)small currents

c)large currents

d)large voltages

31) In a 3 wire system the earth wire is coloured

a)red

b)black

c)white

d)green

32) A power factor meter in ECR shows-

a)true power

b)apparent power

c)relationship between volts and amperes

d)relationship between true power and apparent power

33) Before synchronizing alternators, they must have

a)load equalised

b)same frequency

c)same voltage

d)same amperage

34) The advantage of DC motors over AC motors is that, they have-

a)higher speeds

b)handle heavier loads

c)have better speed control

d)have a longer life

35) Which of the following is not required for synchronizing alternators

a)same voltage

b)same phase rotation

c)same speed expressed as frequency

d)same KW rating

36)Temperatures in AC generators are indicated by-

a)imbedded thermocouples

b)deep well thermometers

c)pyrometers

d)standard thermometers

37) If the resistance of a circuit is doubled and the applied voltage kept constant, the current will-

a)increase 4 times

b)be doubled

c)cut into half

d)no change

38) If the polarity of a DC line is reversed the connecting motors will-

a)stop

b)increase in speed

c)reverse

d)rotate as before

39) Which of the following parts of an AC motor corresponds to the armature of a DC motor-

a)field coils

b)stator

c)rotor

d)armature

40) Which of the following parts of an AC motor corresponds to the field of a DC motor?

a)stator

b)the field coils

c)rotor

d)armature

41) The purpose of a commutator is to—

a)keep a constant voltage

b)rectify armature current

c)convert magnetic lines of force into flux

d)keep a constant amperage

42) If a transformer was plugged into a DC circuit—

a)the fuse would blow

b)the primary would overload and the secondary would be dead

c)the secondary would burn out

d)any of above

43) A fully charged lead acid battery SG reads from—

a)1.28 to 1.30

b)1.02 to 1.07

c)1.46 to 1.48

d)1.16 to 1.20

44) The normal cell voltage of a fully charged lead acid battery is—

a)2 to 2.2

b)1.4 to 1.8

c)1.2 to 1.4

d)5.8 to 6.0

45) A megger is always used on a –

a)grounded circuit

b)live circuit

c)deenergised circuit

d)short circuit

46) A megger is used to measure

a)kilo ohms

b)mega ohms

c)milli ohms

d)micro ohms

47) A megger is a—

a)hand cranked instrument for measuring current

b)hand cranked AC generator

c)hand cranked DC generator

d)meter for measuring thickness of insulation

48) When megger testing a new armature coil to ground-the readings should be at least-

a)1 meg

b)100 megs

c)1000 megs

d)infinity

49) an ammeter is connected to a circuit in

a)series-parallel

b)parallel

c)series

d)contact

50) 60 cycles or Hertz meams the cycle is repeated-

a)60 times a minute

b)60 times an hour

c)60 times a second

d)none of above

51) To reverse the rotation of an AC motor-reverse

a)any 2 of the 3 leads

b)the field leads

c)the armature leads

d)both the field and the armature leads

52) Which of the following is not found on AC generators-

a)slip rings

b)commutator

c)brushes

d)field coils

53) Doubling the diameter of a wire –

a)increases the resistance 4 times

b)reduces the resistance 4 times

c)decreases the resistance 2 times

d)increases the resistance 2 times

54)Field excitation when requires is always supplied from

a)a source of DC

b)an alternator

c)a magnet

c)a selenium rectifier.

55)An oscilloscope can measure—

a)peak voltage

b)frequency

c)phase angle

d)all above

56)For charging a lead acid battery, you allow a current to flow from an external EMF source through the battery

a)in the same direction

b)in the reverse direction

c)current in same and reverse direction alternately.

d)none of above

57) A 2 pole alternator running at 3600 rpm can be paralleled with a 4 pole alternator running at—

a)3600 rpm

b)1800 rpm

c)900 rpm

d)7200 rpm

58) What is the difference between a AC generator and a DC generator—

a)AC generator has a commutator

b)DC generator has slip rings

c)AC generator has slip rings

d)none of above

59) What is the diference between a DC motor and a DC generator

a)DC generator does not have residual magnetism when put off

b)there is no difference

c)DC motor does not have commutator

d)DC motors do not have interpoles

60) If an AC generator on load slows down –

a)current drops

b)frequency drops

c)voltage drops

d)all of above

61) An electrical device for converting DC to AC is called

a)transformer

b)inverter

c)rotary convertor

d)synchronous converter

62) If an AC generator was slowed down, the following would happen within limits

a)voltage would increase

b)amperes would increase

c)frequency would increase

d)all of above

63) A 3 phase system

a)gives 3 distinct voltages out of step with each other

b)has a peak voltage 3 times every 360 degrees

c)is like comparing a single cylinder engine with a 3 cylinder engine

d)all of above

64) Power factor is

a)true power divided by the product of amperes and volts

b)true power divided by apparent power

c)KW divided by KVa

d)all of above

65)After main power is restored, a timed sequential restart of motor-driven auxilliaries is necessary to avoid:

a)Generator overload due to many motors starting at simultaneously

b)Overloading creating earth faults

c)Overvoltage due to current surges

d)Over-frequency due to overspeed of generator

66)A 3-phase induction motor is rated at 200 Amperes. Its initial direct- on-line starting current will be approximately:

a)100A

b)200A

c)50A

d)1000 A

67)An earth fault exists on the blue line of a 100 A bilge pump circuit. A second earth fault occurs on the yellow line of a 10 A ventilation fan circuit. The likely outcome is that:

a)An open circuit occurs between earth fault and both motors trip out

b)Both motors trip out on overload

c)A short circuit occurs between earth faults and the ventilation fan fuse blows

d)A short circuit occurs between earth fault and the bilge pump fuse blows

68)The insulation resistance (IR) to earth of a new galley hot-plate is measured to be 30 Mohm. When three identical hot-plates are tested together their combined IR will be:

a)90 M ohm

b)30 M ohm

c)10 Mohm

d)6 M ohm

69)A motor is protected by a thermal overcurrent relay. After tripping on overload it will not be possible to reset the overcurrent relay because the:

a)Bimetallic strips need time to cool down

b)Starter isolator automatically applies an interlock

c)Oil dash-pot has also to be reset.

d)Line contactor spring also has to be reset

70)A 3-phase A.C. induction motor is running normally at its rated current of 150 A when a single phasing fault (open circuit) occurs in one line. The likely outcome will be:

a)Line currents: 0 A, 150 A, 300 A. Trip condition: trip on overload.

b)Line currents: 75 A, 75 A, 75 A. Trip condition: no trip but speed falls.

c)Line currents: 150 A,150 A,150 A. Trip condition: fuses blow on short circuit.

d) Line currents: 0 A, 180 A, 180 A. Trip condition: trip on overload.

71)The function of the fuses in a motor starter circuit is to provide:

a)Overload protection.

b)Undervoltage protection.

c)Short circuit protection.

d)Open circuit protection.

72)If the A.C. line current in a generator is doubled, the heating effect in the stator windings will be :

a)4 times

b)Same

c)Half

d)Twice

73)When a large motor load suddenly is disconnected from the switchboard and the genarator is AVR controlled, the voltage will:

a)Initially fall, then reset to the set value.

b)Initially rise, then reset to the set value

c)Remain approximately constant, due to governor action.

d)Remain approximately constant, due to AVR action

74)Unloading a generator, it is necessary to gradually decrease the load in order to avoid:

a)Undue overload on the switchboard.

b)Undue overcurrent

c)Undue overspeeding.

d)Undue temperature rise.

75)The pair of instruments necessary for generator synchronising are:

a)Voltmeter and synchroscope

b)kW meter and frequency meter

c)Amp-meter and volt-meter

d)Synchroscope and kVa-meter

76)Prior to synchronising, the generator voltage and frequency are respectively controlled by:

a)Speed governor and load power factor

b)Synchroscope and speed governor

c)Voltmeter and frequency meter

d)AVR and speed governor

77)For ideal synchronising, the phase angle difference between the incomer e.m.f. and the busbar voltage should be:

a)0°

b)30° behind

c)90° lag

d)30° ahead

78)During synchronising, the incoming generator should be running slightly "fast" compared to the busbar frequency.This is to ensure that the:

a)Incomers reverse power trip is tested

b)Incomer picks up as a motor

c)Most rapid synchronising action is achieved

d)Incomer picks up as a generator

79)The correct time to synchronise is usually taken to be when the synchroscope reaches the "5 to 12" position. This to allow for:

a)Synchroscope pointer time lag

b)Circuit breaker operating time

c)Synchroscope error

d)Generator phase difference error

80)Generator 1 and 2 are working in parallel. Prime-mover 2 suffers a total fuel loss. The likely outcome is:

a)No.2 generator trips on reverse power

b)Generator set 1 trips on reverse speed

c)No.1 machine overloads and trips out on overspeed

d)No.1 machine overspeeds and trips out on overload

81) You have just syncronized a second alternator onto the main switchboard, and want to equally share the load between the "on" and incoming alternators. What would you do first?

a)Adjust voltage rheostat for the incoming alternator on the front of the switchboard

b)Lower the governor speed controller of the incoming alternator and increase the governor speed controller of the alternator already on the switchboard

c)Trip the circuit breaker of the incoming alternator and check the voltage and speed adjustments before trying again

d)Raise the governor speed controller of the incoming alternator and reduce the governor speed controller of the alternator already on the switchboard

82) Advantage of Ni Cad battery

a)no need to top up

b)no damage due to short circuit

c)no corrosive/ explosive vapours

d)all above

83) At which point do you engage the main circuit breaker of the incoming alternator when paralleling two alternators?

a)With the pointer of the synchronoscope rotating fast and both synchronizing lamps flashing on and off

b)In none of the mentioned alternatives

c)With the pointer of the synchronoscope at 0° (12 O'clock) and both synchronizing lamps dark (off)

d)With the pointer of the synchronizer stopped at any position and both synchronizing lamps bright (on)

84) With no.1 and no.2 alternators running in parallel and the kW loads equally shared, one alternator is drawing much higher current than the other. What does this indicate?

a)Alternator frequencies are different and should be adjusted on the governor speed controllers

b)Alternators are out of phase and should be tripped and paralleled again

c)One alternator has lost one of its phases

d)The alternators are not generating the same voltages and should be adjusted on automatic voltage regulator rheostats

85) With two alternators running in parallel, you wish to stop one. The first step is to:

a)Remove the load from the alternator to be stopped

b)Make sure the load is evenly shared

c)Trip the main circuit breaker

d)Increase the frequency on the switchboard

86) You are paralleling two alternators and the pointer of the synchronoscope slowly stops rotating and remains stopped in one position before the circuit breaker is closed. This would indicate:

a)The frequency of the incoming alternator is the same as that of the main switchboard

b)The synchronoscope is not functioning properly and should be checked

c)The voltage of the incoming alternator is the same as that of the main switchboard

d)The incoming alternator is in phase with the switchboard, but the frequency is not the same

87) A 450 volt, 859 kW rated generator has not been in operation for several weeks. Prior to starting, insulation resistance readings are taken. The minimum acceptable insulation resistance reading on the main stator winding to allow you to proceed with running the generator is:

a)10 000 000 Ohms

b)10 0000 Ohms

c)10 000 Ohms

d)10 00 Ohms

88) On regular inspections of alternator windings it is found that windings are always covered with a heavy oil film coming from the atmosphere surrounding the auxiliary engine. After cleaning with an approved solvent, what do you do?

a)Take no additional action

b)Blank off intake air filters

c)Reinsulate the windings after each cleaning

d)Improve material of intake air filters

89) On routine daily inspection you notice that there is a light arching between an alternator's carbon brushes and rotor sliprings, with alternator operating at 70% load. Should you:

a)Increase the tension on the brushes

b)Reverse the polarity of the excitation voltage at the brush holder connection

c)Move the position of the brushes around the sliprings to find the correct neutral position

d)Check the surface of the sliprings, polish if necessary and bed in the brushes

90) What is the purpose of the alternator reverse power trip?

a)To prevent parallel operation if the excitation field voltage is reversed

b)To prevent the alternator from being paralleled if it is out of phase with the main c)switchboard

d)To prevent the alternator from "motoring" by being supplied power from other parallel alternator

91) If you alter the field excitation voltage of one alternator operating in parallel, this will cause change in that alternators:

a)Reactive load (kVAR)

b)Frequency

c)None of the mentioned alternatives

d)Active load (kW)

92) The automatic voltage regulator is used to control the output voltage of the alternator at varying load conditions by:

a)Varying the excitation field strength by regulating excitation voltage/current

b)Regulating the voltage signal to the engine governor to regulate the speed to the desired load condition

c)Supplying variable current to compounding and no load transformers in the alternator stator winding circuit

d)all of the mentioned alternatives

93) The power requirements for the excitation winding/circuit for a 3-phase alternator operating at rated output power are supplied by:

a)Independent battery supply

b)Independent power supply and rectifier unit

c)The main switchboard via a three phase rectifier

d)The alternators output itself via the automatic voltage regulator

94) A three phase alternator is connected singularily to the main switchboard. The switchboard instruments show 440 Volts/950 amperes. With a power factor of 0.8 what will be the kW load?

a)215.9 KW

b)418 KW

c)334.4 KW

d)579.2 Kw

95) Before taking insulation resistance readings of generator windings the automatic voltage regulators should be isolated and all semiconductor short circuited or disconnected in order to:

a)Prevent charging of capacitive components within the automatic voltage regulator causing false regulation when generator restarts

b)Prevent operation of automatic voltage regulator during insulation testing

c)Prevent damage to sensitive electronic components from high voltage tester

d)Protect insulation resistance tester from being damaged

96) Following circuits are NOT used in digital computers

a)AND gate

b)NOT gate

c)IF gate

d)OR gate

97) megger readings versus temperature – 1 mega ohm at 75 deg c is equivalent to how much at 25 deg c.

a)1 mega ohm -- no change

b)30 mega ohms

c)1.2 mega ohms

d)0.7 mega ohms

98)the black terminal probe of the multimeter is

a)positive terminal

b)negative terminal

c)common terminal

d)earth terminal

99) a star delta starter

a)used for large motors like bow thruster

b)starting torque and starting current reduced to 1/3

c)long starting time

d)all above

100)direct on line starter

a)less time taken

b)can be started at full load

c)starting current is 7 times more than full load current

d)all above

ANSWERS:

1B2D 3C4C 5B6C 7B 8C 9B 10B 11D 12D 13D 14B 15C

16D 17A 18C 19A 20B 21B 22C 23D 24B 25B 26D 27A 28D 29A 30B 31D 32D 33B 34C 35D 36A 37C 38D 39B 40C 41B 42B 43A 44B 45C 46B 47C 48A 49C 50C 51A 52B 53B 54A 55D 56B 57B 58C 59B 60D 61B 62B 63D 64D 65A 66D

67C 68C 69A 70D 71C 72A 73B 74C 75A 76D 77A 78D 79B 80A 81D 82D 83C 84D 85A 86A 87A 88D 89D 90D 91A 92A 93D 94D 95C 96C 97B 98C 99D 100D

1) 1 ppm of chlorides in water means

a)1 mg/ litre

b)1 mg/ cum

c) 1 mg/ cc

d)none of above

2) Quality of the feed water in a steam plant changes during operation. Caused by this, the water is regularly tested. Which of the below statements describes the chemical mechanisms normally occuring?

a) Generation of carbonic acid causes the water quality to drift towards sour and lower the pH - number.

b) Generation of sulphur acid causes the water quality to drift towards sweet and rise the pH - number.

c) All of the mentioned alternatives.

d) Water is becoming sligthly less conductive and does not transfer heat.

3)Normally a boiler water sample should be taken

a)after the boiler has been blown down

b)before the boiler has been blown down or chemicals added

c)when the boiler has been refilled with makeup

d)from the highest point in the feed system

4).What is the main purpose of bottom-blowing a boiler?

a) To get rid of sludge in the water chamber.

b) To control that water is present in the water chamber, when the boiler is in active operation.

c) To adjust steam pressure when the burner capacity is excessive.

d) To check that we do not have any leak of smoke and gases in the combustion chamber.

5)Which of the following procedures decreases the total dissolved solids concentration in the water of an auxiliary boiler?

a)Hydrazine treatment of condensate

b)Frequent compounding

c)Chemical cleaning

d)Bottom blowing

6).What is an effective means of measuring total dissolved solids in boiler water?

a) Conductivity test.

b) Alkalinity test.

c) Chloride test.

d) Not possible to test solids in boiler water.

7) Dissolved oxygen can be removed from the boiler water by

a)frequent surface and bottom blows

b)dumping and refilling the boiler weekly

c)passing the water through absorbent filters

d)treating the water with chemical scavengers

8).What initial simple recommendation can we give to reduce oxygen in the boiler water?

a) Raise the feed water temperature.

b) Lower the feed water temperature.

c) Increase the boiler pressure.

d) Increase the "Blow down".

9)A continuous blow is used to

a)regulate the density or salinity of boiler water

b)remove scum from the surface of boiler water

c)permit air to excapewhile raising steam in a cold boiler

d)remove sludge from the bottom of the water drum

10).What will you do if the PH-value in the boiler water is over 11?

a) Blow the boiler and renew water until the PH-value is normal again.

b) Increase the dosage of chemicals.

c) Decrease the dosage of chemicals.

d) Nothing.

11)The end product of reactions occurring when boiler water is chemically treated, remain in the boiler and increase the need for

a)acid cleaning

b)makeup feed

c)boiler blowdown

d)waterside corrosion treatment

12).Which of the below listed effects can be caused by the presence of Calcium in the boiler water?

a) Loss of alkalinity, corrosion of boiler metal surfaces, and loss of phosphate reserve in the boiler.

b) Passifying of boiler metal surfaces.

c) Increase of alkalinity and PH-value.

d) No negative effects.

13)The greatest deterrent to heat transfer from the fireside to the waterside of a boiler is

a)water film

b)water eddies

c)gas film

d)gas eddies

14).For a low pressure boiler, after testing the water, You found the Chloride level to be 50 PPM, what action would You take?

a) Do nothing.

b) Increase dosage.

c) Blow down the boiler and reduce dosage.

d) Reduce dosage.

15)Oxygen corrosion in auxiliary boilers is prevented by treating the boiler feed tank with either sodium

a)sulfite or hydrazine

b)sulfite or hygroscopic sulfite

c)bromide or hydrazine

d)bromide or hygroscopic sulfite

16).For a low pressure boiler, after testing the water cloride level, it is found to be 500 PPM, what action would You take?

a) Blow down boiler and check condenser for leakage.

b) Do nothing.

c) Decrease dosage.

d) Increase dosage.

17)The MOST common cause of heat blisters developing on boiler generating tubes is due to

a)waterside deposits

b)fireside deposits

c)low water level

d)insufficient water circulation

18).If oil is found in the boiler water, what action would You take other than isolating the leak?

a) Dose with coagulent and blow down the boiler.

b) Blow down the boiler.

c) Do nothing.

d) Dose with coagulent.

19)Oil deposits can be removed from the waterside of boilers by "boiling out" with a/an

a)alkaline solution

b)acid solution

c)salt solution

d)kerosine solution

20).In a low pressure auxiliary boiler, what would you consider to be the maximum allowable chloride level?

a)300 PPM.

b)30 PPM

c)10 PPM

d)50 PPM

21)Oxygen content of boiler feed water at 50C is –

a)same as water at 90C

b)twice more than water at 90C

c)thrice more than water at 90C

d)4 times more than water at 90C

22.In a low pressure auxiliary boiler, what would You consider to be the normal operating range of phenolphthalein alkalinity—PPM CaCO3 ?

a)100 - 300

b)1-6

c)30-60

d)8 to 28

23)The bottom blow to remove solid matter ( not salinity ) of boiler is done by

a)one short blow with boiler running

b)one long blow with boiler cut off

c)several short blows when boiler is cut off

d)several short blows with boiler running.

24)On a chemical tanker discharging palm oils in Baltic in winter, some palm oil traces are found in the hotwell. This will cause –

a)foaming in the boiler

b)fluctuating water level in drum

c)wet steam on deck

d)all of above

25)What when present in boiler feed water causes scaling

a)sodium carbonate

b)sodium suphate

c)calcium sulphate

d)hydrazine

26)Impurities in boiler feed water causes-

a)scale formation

b)corrosion

c)water carry over

d)all of above

27)Boiler water reading records shall be available on board ,as per class rules of -

a)chlorides/ phosphates

b)pH

c)Oxygen

d)All above

28)Common chemicals used to prevent formation of boiler tube scales are

a)calcium phosphate

b)magnesium hydroxide

c)sodium chloride

d)sodium phosphate

29)Thermal deaeriation in cascade tank/ hotwell removes dissolved oxygen up to—

a)10%

b)50%

c)95%

d)75%

30)Oxygen remaining after thermal deaeration is removed by chemical scavenging using

a)Hydrazine

b)sodium phosphate

c)sodium hydroxide

d)caustic soda

31)Sodium sulpite chemically combines with oxygen to form—

a)Nil dissolved solids

b) dissolved salts

c)nitrogen

d)none of above

32)Hydrazine causes—

a)cancer

b)tuberculosis

c)asthma

d)safe for use

33)Water / steam side of boiler is passivated at pH

a)3.5 to 5

b)10 to 11

c)13 to 14

d)7

34)Alkaline water changes from pink to colourless phenolphethelein at

a)8.3

b)12.9

c)1.8

d)2.9

35)Boiler water is tested for correct alkalinity to—

a)precipitate hardness salts to prevent scale

b)passivate with Fe3O4 film

c)maintain silica in solution to prevent scale

d)all above

36)Feed water and condensate pH value should be—

a)11 to 12.1

b)8.3 to 9

c)7 to 7.3

d)6.4 to 7.6

37)Boiler water pH should be in the range of

a)8 to 8.9

b)9.5 to 11

c)3.4 to 5.8

d)13 to 13.2

38)Cooling fresh water pH value should be-

a)8.3 to 10

b)12 to 13.1

c)5.2 to 7.1

d)7

39)Boiler feed water chloride value should be less than

a)0.249 ppm

b)3 ppm

c)15 ppm

d) 200 ppm.

40)Cooling fresh water ppm for chlorides should be max—

a)50

b)300

c)3

4)0.249

41)Hydrazine does the following—

a)scavenged dissolved oxygen

b)reduced red oxide to black oxide

c)raises the pH of condensate and feed water systems

d)all of above

42)Boiler feedwater testing is for—

a)hardness

b)oxygen

c)chlorides

d)all above

43)Factors affecting boiler water tube corrosion are

a)cavitation

b)dissolved solids gases

c)micro organisms

d)all of above

44)Condensate testing is for

a)pH

b)chlorides

c)ammonia

d)all above

45)The main purpose of boiler water treatment is to—

a)reduce hardness

b)increase pH

c)remove oxygen

d)all of above

46)Water carry over in boiler steam can be caused by

a)high concentration of dissolved solids

b)high alkalinity of feed water

c)high concentration of suspended solids

d)all of above

47)If oil enters the boiler, it will coat the

a)top tubes

b)bottom tubes

c)both top and bottom

d)middle tubes

48)Adding Hydrazine hydrate N2H2 to boiler water

a)removes oxygen

b)makes iron oxide sludge non adherent

c)increases alkalinity

d)all of above

49) It is better to provide a large volume of cooling water with a slight temperature differential between inlet and outlet cooling lines , than to provide a lesser but colder flow, with the same outlet temp

a)to avoid vapour pockets and local hot spots

b)to avoid scale deposition

c)to avoid thermal shock to liner due to cold water inlet

d)all of above

50)Sea water has ppm salt

a)330 ppm

b)3300 ppm

c)33000 ppm

c)33 ppm

Answers:

1a 2a 3b 4a 5d 6a 7d 8a 9a 10a 11c 12a 13c 14a 15a 16a 17a 18a 19a 20a 21d 22a 23c 24d 25c 26d 27d 28d 29d 30a 31b 32a 33b 34a 35d 36b 37b

38a 39c 40a 41d 42d 43d 44d 45d 46d 47b 48d 49d 50c