- Screw pump is normally used for
- fluid with high viscosity,
- better performance at variable temp,
- fluid mixed with solids
- all the above
ANS.: D
- Steel carbon equivalent > 0.5%
- good weld ability,
- medium we debility,
- poor weld ability,
ANS.: C
- In a centrifugal pump the fluid enters
- Through eye of impeller
- At tip of impeller
- Middle of impeller
- None of the above
ANS.: A
- Which of the following statements is true?
- Corrosion is physical phenomenon while erosion is a chemical phenomenon
- Corrosion is a chemical phenomenon while erosion is a physical phenomenon
- Corrosion may be because of chemical or physical action while erosion is due to physical action only
- Corrosion is a chemical phenomenon while erosion may be due to chemical or physical action
ANS.: B
- Whenever a F.O. heater is put into use it should first be ________ by using the ___________to prevent ____________. Fill in the blanks using the correct set of options
- Drained, drain valve, overpressure of heater
- Heated, steam inlet valve, blockage of heater
- Pressurized, F.O. outlet valve, pressure drop in F.O. line
- Purged of air, vent valve,vapour/air lock inside the heater
ANS.: D
- WHEN BOTH PUMPS OF STEERING GEAR ARE IN OPERATION
- PILOT ON BOARD
- WHEN 12NM AWAY FROM LAND
- FOR NAVIGATIONAL SAFETY
- WHILE MANOUEVRING
ANS.: 1,2,3
- You have dismantled a centrifugal pump having a double entry impeller, but forgot to do the markings while dismantling. During installation what will you do?
- Double entry impellers are identical when seen from both the sides and can be used either way and actually no marking is necessary
- Even if the impeller is wrongly placed, the pump can still function if we change the phase sequence of the driving electric motor
- Hit and trial method will be used by assembling the pump and trying it out after putting the impeller in one way
- Direction of rotation and/or the shape of the volute casing will help you to put the impeller in the correct way
ANS.: D
- Intercoolers in multistage compressors _____________
- Reduce the work done in successive stages of compression
- Allow for moisture to be drained between stages
- Increase volumetric efficiency
- All of the above
ANS.: D
31. Impingement corrosion can be best avoided during pipeline system design by
- Keeping flow velocities to a minimum
- Keeping fluid temperatures low
- Avoiding conditions leading to cavitation and turbulence
- Keeping working pressures in the system high
ANS.: C
SECTION – 4
1.Your ship is plying in coastal waters in India which is muddy most of the time. Your main sea water pump shaft mechanical seal develops leak every time you are in a port and wears out very fast. What is the cause of the problem(choose the best alternative):
- The mechanical seals are not of good quality
- Seal spring pressure is too high and should be adjusted to a lower value
- Mechanical seals are not designed to work with dirty and abrasive fluids
- Supply of cooling water to the seal faces is insufficient due to muddy waters
ANS.: C
2. Which of the following instruments is used to measure rudder carrier bearing wear down?
- Poker gauge
- Telescopic feeler gauge
- Depth gauge
- Trammel
ANS.: D
3. Which one of the following methods of metal coating provides best protection against corrosionresistance :-
- Hot dipping
- Metal Spraying
- Electroplating
- Metal Cladding
ANS.: C
- brass/bronze/gunmetal composition
- 80% Cu, 20% Zn 60%-
- copper 39.25% – zinc .75%—-
- copper 85%.tin5%.lead5%. zink5%
- cu 88%,tin 10%, zinc 2%
ANS.: D
6. Auxiliary engine crank pin bearings are normally renewed:
- During every de-carbonization
- During every alternate de carbonization
- Depending on the condition of the bearings
- After every 10000 hours
ANS.: C
7.Which of the following is not a method of cleaning a turbocharger, while it is in operation?
- Wet cleaning of turbine side
- Dry cleaning of turbine side
- Wet cleaning of the blower side
- Dry cleaning of the blower side
ANS.: D
8. Noble metals are those which are placed at the
- Top of electrochemical series , having high negative corrosion potential
- Bottom of electrochemical series , having low negative or positive corrosion potential
- Only those having zero corrosion potential
- None of the above
ANS.: B
9. During auxiliary engine de-carbonization, which of the following checks need to be carried out?
- Sounding of all double bottom tanks
- Connecting rod big end ovality
- Liner wear
- Crack detection tests on connecting rod serrations
ANS.: 2,3,4
10.Why is use of Polymer treatment restricted to low-pressure boilers?
- It does not effectively control sludge formation.
- It does not effectively control scale formation.
- It has no PO4 present to counter caustic alkalinity
- All of the above
ANS.: C
11.Throttling the discharge valve of a centrifugal pump the NPSH
- Increases
- Decreases
- NPSHr remains constant depending on pump design and only NPSHa changes
- Both the NPSHr&NPSHa will remain unaffected by throttling of discharge valve
ANS.: B
12.In an electrochemical series the metals having higher negative potentials are placed on top, while those with lower negative potentials or positive potentials lie at the bottom. Which one of the following is a true statement?
- Metals lying high up in the series can provide protection to those lower in the series
- Metals high up in series can be used as sacrificial anodes for those lying below them
- Metals lying at the top of series are called as noble metals
- None of the above
ANS.: B
14. Double entry impellers have a distinct advantage over single entry impeller. What is it?
- They balance out the axial thrust
- It gives a higher pumping efficiency
- It is cheaper and easier to manufacture
- The need of installing line bearing onto the pump shaft is eliminated
ANS.: A
- The steels with a carbon percentage close to 0.8% have
- poor strength but good weld ability
- High strength but poor weldability
- Poor strength and poor weldablity
- High strength and good weldability
ANS.: B
- Auxiliary engine connecting rod’sbottom end bolts should be tightened:
- Only as per the prescribed torque using a torque range
- As per prescribed torque as well as angular measurements as recommended by the manufacturer.
- By following previous match marks on bolt heads and connecting rod body
- As per prescribed torque and another 10% increase during every subsequent tightening
ANS.: B
- Which of the following statements are true as far as painting of steel hull/structure is concerned? Multiple choices
- Painting can be done under any weather condition
- Painting can only be done after proper surface preparation is carried out
- Painting should only be done on top of appropriate primer coating
- Several coats of paint can be applied one after the other without any time gap
ANS.: 2,3
- A reciprocating pump is used for Engine room bilge service because:
- Reciprocating pumps are designed for smoother discharge
- Only small capacity pumping capacity is required, while other pumps are of higher capacity
- It doesn’t churn and mix the bilge water unlike other types of rotary and roto-dynamicpumps
- Shipbuilding industry is still going on old concept, future ships will have centrifugal pumps installed
ANS.: C
- Fire side in boilers gets commonly corroded due to:
- Galvanic action
- Formation of Vanadium pentad oxide and sulfuric acid
- Stress corrosion
- Crevice corrosion
ANS.: B
- NPSH and the Total suction head are two terms which are commonly used for pumps. Which of the following is a true statement?
- They are one and the same thing
- Total suction head is greater than NPSH
- NPSH is always greater than Total suction head
- Total suction head and NPSH have no relationship
ANS.: B
- Which of the following can cause exhaust with black smoke in a diesel engine?multi choice
- Choked air filter of turbocharger
- Water mixed with fuel
- Bad atomization of fuel
- Overload
ANS.: A,C,D
- Before putting into operation a coalesce type Oily Water Separator, it is important to:
- Fill it up with purge water
- Drain it completely
- Switch off the heater
- Keep the three way valve manually open
ANS.: A
- Ship is in drydock, stern tube seal renewal has been carried out, hw will check for the leak
- fill the system with oil to the maximum level in header tank
- fill the system with oil to just fill the stern tube
- fill the aft seal and forward seal tank to the deepest draught
- refloat the vessel to check for any leaks
ANS.: D
- The function of an accumulator on the discharge side of a reciprocating bilge pump is to:
- Supply liquid even when the pump is not running
- Dampen out the pressure pulses and smoothen the flow
- Increase the discharge pressure by storing liquid under pressure
- No such device is required to be fitted to modern bilge pumps
ANS.: B
- Sequence of metal in the increasing order of nobility in galvanic series
- Stainless steel, Mild steel, Copper, Zinc
- Copper, Stainless steel, Mild steel, Zinc.
- Zinc, Mild steel, Stainless steel, Copper.
- Zinc, Copper, Stainless steel, Mild steel
ANS.: C
- While re-floating the vessel after dry dock, which of the following checks should be carried out?
- Sounding of all double bottom tanks
- Checking leakages in the stern tube header tanks
- Checking leakages at ship side valves
- Checking levels of stern tube header tanks
ANS.: 1, 3, 4
- Which of the following anodes in an ICCP can be used for comparatively higher current densities:-
- Zinc
- High silicon Iron
- Lead-silver
- Platinized Titanium
ANS.: D
- A centrifugal pump may fail to deliver water when first started if the
- Water seal pipe is plugged
- Pump is not primed
- Seal ring is improperly located
- All of the above
ANS.: B
31, The diameter of the branch suction pipe referred to in item 118 shall not be less than that derived in accordance with the following formula, taken to the nearest 5 mm:
Lowercase d equals 25 millimeters plus 2.16 times the square root of the product of C times the sum of B and uppercase D where:
d – is the internal diameter of the branch suction pipe, in millimetres
C – is the length of the cargo hold, in metres
B – is the greatest moulded breadth of the ship in metres
D – is the moulded depth of the ship to freeboard deck, in metres
d=2.16*sq root[C(B+D)] +25 mm
- What to check if Engine is not taking load?
- Water tightness to be checked.
- Air to be removed from jacket water outlet line.
- Priming lube oil pump to run before starting the engine.
- Check the lube oil level.
- Check the flow of lube oil.
- Blow through the engine before starting
ANS.: 1,2,3,4,5,6
33.Which of the following cannot be used as sacrificial anode for the protection of Mild steel structure against corrosion :
- Cadmium
- Magnesium
- Copper
- Aluminium
ANS.: C
- When centrifugal pump is changed over for pumping a liquid of higher specific gravity which of the following is going to change?
- Discharge pressure
- Discharge head
- Power consumption
- Pump speed
ANS.: C
- When centrifugal pump is changed over for pumping a liquid of higher specific gravity which of the following is going to change?
- Discharge pressure
- Discharge head
- Power consumption
- Pump speed
ANS.: A,C
35.In a reciprocating pump the direction of flow depends upon:
- Direction of rotation of the pump
- Position & fixing of suction and discharge valves
- High pressure to low pressure
- Whether pump is single acting or double acting
ANS.: B
36.Net Positive Suction Head is theNPSH
- Difference of Total suction head and Total discharge head
- Difference of static head and the frictional head
- Difference of dynamic suction head and the vapour pressure of liquid
- Difference of Static suction head and the vapour pressure of liquid
ANS.: D
54. what is the best percentage of carbon content in stainless steel which allows welding?
- 0.35
- 0.45
- .55
ANS.: A
55.why centrifugal p/p not provided with safety valve while positive displacement p/p is provided?
- c/f p/p shut down head is 0
- c/f p/p shut down head is infinity
- c/f p/p is so designed that it can withstand high pressure
ANS.: C
57. Fridge comp. running continuously without cutout
- Air in refrigeration
- Overcharge
- Undercharge
- Excessive cooling load
ANS.: D
59. Sea suction filter holes corroded and size increased, what can be done
- Run without filter no problem to p/p
- Order for new till then run with the same filter
- Do mechanical repair and run the same until new filter comes
- Run the same filter no problem
ANS.: C
60. Insulation Resistance testing of 3 phase induction motor is done
- Phase to phase
- Earth to body
- Phase to earth
- Both a and b
ANS.: C
- In M/E Lo Cooler, Lo Should Pass Through:
- shell
- tube
- either shell or tube
- none of the above
ANS.: A
63: When securing a centrifugal distillate pump, which of the listed steps should be carried out FIRST?
- A.Stop the pump.
- B.Close the pressure gage valves.
- C.Trip the three-way solenoid valve.
- D.Close the sealing line valves to the pump
ANS.: C
- Dezincification is the term used to describe
- Loss of zinc an alloy due to formation of internal bimetallic cells due to different alloying elements
- Loss of zinc due to external bimetallic cells between zinc alloy and another dissimilar metal or alloy
- Removal of zinc from an alloy by precipitation from Eutectic solution
- Removal of zinc from an alloy by dissolving the alloy in a zinc dissolving chemical
ANS.: D
- Fixed vane type Emergency Fire Pump is priming Vacuum pump. After one week fire pump is not taking suction. The vacuum pump is engaging, but not developing vacuum in the suction side. What will be the cause?
- Suction filter of the pump clogged
- Suction filter cover gasket leaks
- Vacuum pump not overhauled properly
- Sealing water tank is empty
ANS.: D
66.What is the purpose of the Bypass valve ( Automatic or Manual operated) on the positive displacement pump?
- Control the Discharge Pressure
- Another valve provided for Discharging
- Not required
- I don’t know
ANS.: A
67.When specified Discharge pressure is not achieved, The Possible cause could be?
- Discharge pressure too high
- Pump speed too low
- Casing ring is worn out
- Cavitations exists
- All of the above
ANS.: 2,3,4
68.When steel components electroplated with chromium are used in a corrosive Environment then
- A. Chromium plating provides corrosion protection to the steel components
- Chromium plating cannot provide corrosion protection as steel willbe preferentially corroded
- Zinc plating is to be used on top of chromium plating forcorrosion protection
- Thickness of chromium plating is required to be increased forcorrosion protection
ANS.: A
69.The amount of current needed for hull protection in case of ICCP system for a particular ship will be most affected by :-
- Wetted surface area
- Quality and condition of protective paint coating
- Speed of the ship
- Sea water temperature
ANS.: 1, 2, 3
- Polymer treatment is restricted only to low pressure boilers because
- It cannot prevent sludge formation
- It cannot prevent scale formation
- It cannot prevent po4 formation
- All the above
ANS.: C
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