Top Marine Engineering Objective Questions

1.What is motor bike c.c.?

cubic/centimeter

2.How the priming is done in a centrifugal pumps?

As centrifugal pump is not a self priming pump,separate priming arrangement is required…generally,a separate axial pump is provided for this purpose.The discharge v/v of the centrifugal pump is closed,and the inlet v/v is opened.The discharge v/v is opened only after the pump is primed,that is filled with the liquid to be pumped.

3.What is the different between gate valve and globe valve?

Gate valve is non regulator means full close or full open positions only, while globe valve is regulator.

4.What is the purpose of o-ring, wearings in the centrifugal pumps?

O-ring :

to prevent leakage between metal parts while allowing some movement between them wear ring : generally a softer material than the parent material , employed to wear out quickly than the parent metal thereby avoiding loss of parent metal

5.what is the difference between Mitsui MAN b&w and Hitachi MAN b&w engines?

Design and system wise absolutely no difference. Only the license manfacturer is different. mitsui and Hitachi
kawasaki Diawoo are the different license holders for Man B&W for making the engines

6.How will we know, without opening anything,that an engine is 2S or 4S?

by the arrangement of the valves …in two stroke exhaust valve is situated at the top(i.e cylinder head) and there are scavenge ports at the bottom in modern diesel engine…whereas in four stoke the exhaust and inlet is situated at the cylinder head.

7.How the power has taken from a large marine generator to the msb?

The 440v generated by the generator can be taken to the MSB via busbars. associated with preferential trips, overload protections

8.What is the meaning of code number which is given on bearing?

bearing number ia 6205z:

6 stands for the type of bearing , ie, deep groove ball bearing

2 standa for the the OD and width (thickness) of the bearing

05 stands for the ID of the bearing ie, 05 x 4= 20 mm bore;

9.In ship cranes, there is a provision of providing a conveyor for the cable. There is no provision of slip ring.How is it possible?

There r Slip ring arrangement in cranes onboard ships. the slip rings are present within the crane which is not seen from outside. the power lines pass throough the centre of the crane through slip rings. The power line u see out side is only for grab which comes through the torsion clutch. If there is no slip ring arrangement the crane cannot turn 360 degrees.

10.Which country level having below the means sea level?

Narve sweedan

11.What does 7L67GFCA stands forin a marine engine MITSUI B&W 7L67GFCA?

7L 67GFCA Means that the engine have seven in-line units (cylinders)with 67centimeter of Liner diameter,water cooled and super charged cross head engine.

12.What is high temperature corrosion and what is center priming?

When material exposed to high temperature atmospehic situation like high level of oxygen presence, sulfer presence and different type chemical presence cause matrial worsening . This type of material corrosion is known as High temperature corrosion

13.What is specific fuel consumption and how fuel calculate?

generally it�s refer to the fuel consumtion rate, there are several deferent way to catlculate the specific fuel
consuption, such as volumetric method and flow method. but these methods can be taken only in lab. no possible do it on the sea.

14.How many types of ships?

Ships are divided into various types depending on their nature of service.

1. Cargo Ships (Bulk carriers, general cargo carriers,container vessels, oil tankers, chemical tankers, product tankers, gas carriers, Ro-Ro ships). Depending on their sizes they are again classified as handymax, panamax,suezmax, afromax, vlcc, ulcc, vloc, vlgc, etc.

2. Passenger Ships

3. Serivce ships, such as cable laying submarines, off shore supply vessels, dp vessels etc

4. Protection such as war ships, Navy submarines etc.

15.The place where happen iron losses?

In transformer case Core occurs iron loss (Eddy Current & Hysteresis Loss) Or No Load Loss in Electric Transformer.

16.How many ports are there in India?

there are 12 major ports and 181 minor port in india

17. The pressure produced within the oil wedge of a rotating journal is . . .

(A) the same as the pressure in the lubricating system.
(B) less than the pressure in the lubricating system.
(C) greater than the pressure in the lubricating system.
(D) highest at the oil groove location.

Ans :A

18. Which of the below listed main shaft segments that are connected with the main engine are coupled to the tail shaft flange?

(A) Thrust shaft
(B) Stern-tube shaft
(C) Intermediate shaft
(D) Crank shaft

Ans :C

19. The ambient heat in an engine room that is identified by only a change in temperature is known as . . .

(A) sensible heat.
(B) latent heat.
(C) total heat.
(D) residual heat.

Ans :A

20. The usual number of single-acting pistons used in a variable stroke axial-piston pump used for steering gears is . . .

(A) 3 or 5.
(B) 5 or 7.
(C) 7 or 9.
(D) 9 or 11.

Ans :C

21. When air attains the maximum amount of moisture it can hold at a specific temperature, it is said to be . . .

(A) superheated.
(B) saturated.
(C) condensed.
(D) convected.

Ans :B

22. Maximum lube oil system pressure is normally controlled in a diesel engine 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

Ans: A

23. 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 likelihood of air or steam pockets formation
(C) Provides a low pressure point for the addition of makeup cooling water
(D) All of the above

Ans:D

24. In comparison to exhaust valves, intake valves of diesel engines may be fabricated from low-alloy steels because . . .

(A) the beveled edges of the intake valves provide for self-centering during seating.
(B) intake valves utilize stellite-coated valve seat inserts which reduce wear.
(C) the volume of air passing through intake valves is less than the volume of air passing through exhaust valves.
(D) intake valves are less affected to the corrosive action of exhaust gases.

Ans:C

25. 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.

Ans :B

26. Which of the bearings listed are most widely used for the main and connecting rod bearings of a 4 stroke medium speed diesel engine?

(A) Roller
(B) Sleeve
(C) Precision insert (bimetal or trimetal)
(D) Needle

Ans :C

27. Prior to lighting off a cold automatically fired auxiliary boiler you should . . .

(A) check and regulate the water level.
(B) close the air cock once fires are lit.
(C) blowdown the gauge glass.
(D) crack open the steam stop valve to assure protective steam flow.

Ans :A

28. Within the cycle of a forced circulation auxiliary water-tube boiler, part of the water flashes into steam, and the remaining hot water is . . .

(A) collected in the lower portion of the steam accumulator for recirculation back to the heating coil or water tank.
(B) returned to the lower drum via downcomers due to density difference for reheating.
(C) passes through the domestic heating system return line steam traps to the auxiliary feed supply tank.
(D) automatically dumped into auxiliary feed heater and reheated by auxiliary exhaust back pressure.

Ans :B

29. Ignition failure in an automatically controlled auxiliary boiler could be caused by . . .

(A) carbon deposits on the flame scanner.
(B) high fuel oil temperature.
(C) low fuel oil viscosity.
(D) high steam pressure.

Ans :A

30. Subtracting the return flow meter reading from the supply flow meter reading on a boiler equipped with a return flow fuel oil system, determines the amount of oil . . .

(A) circulated by the system.
(B) burner throughput.
(C) returned to the settler.
(D) discharged from the pump.

Ans :B

31. If the feed pump for an auxiliary boiler fails to deliver the feed water to the boiler, the cause may be . . .

(A) high steam pressure in the boiler.
(B) abnormally high feedwater temperature.
(C) abnormally high boiler water temperature.
(D) steam demand exceeding feed pump capacity.

Ans :B

32. A vessel’s center of gravity is lowered when the . . .

(A) freeboard is increased.
(B) tanks are ballasted.
(C) reserve buoyancy increases.
(D) trim is increased.

Ans :B

33. Which of the listed conditions will occur to the ships center of gravity if 200 tons of steel is transferred to the ships cargo hold from shore side?

(A) The reserve buoyancy will rise.
(B) The center of gravity will remain in the same position.
(C) The center of gravity will be lowered.
(D) The reserve buoyancy will remain the same.

Ans :C

34. What is the usual effect of moving weight from the main deck to a position lower in the vessel?

(A) The stability of the vessel is increased.
(B) The trim of the vessel is changed substantially.
(C) The stability of the vessel is significantly decreased.
(D) The vessel will list in proportion to the volume of the cargo shifted.

Ans :A

35. Ships are less stable when water or fuel tanks are partially filled because of the . . .

(A) free surface effect.
(B) increase in buoyancy.
(C) decrease in draft.
(D) reduction in trim.

Ans :A

36. Excessive free surface occurring in tanks carrying liquid cargo should be avoided in order to . . .

(A) maintain hog and sag.
(B) maintain good stability.
(C) prevent oil pollution.
(D) all of the above

Ans :B

37. Which of the following describes the purpose of a striker or doubler plate?

(A) Provides a surface for the application of force, or the installation of machinery
(B) Provides landing surface for the sounding bob of a tank sounding tape
(C) Absorbs machinery vibration
(D) Prevents valve stem over travel

Ans :B

38. Stern tube and strut bearings lined with hardwood or rubber composition materials are lubricated with . . .

(A) Saltwater.
(B) Graphite.
(C) light lubricating oil.
(D) heavy lubricating oil.

Ans :A

39. Water leaking through the stern tube stuffing box is used to accomplish which of the following actions?

(A) Cooling
(B) Lubrication
(C) Flushing
(D) all of the above

Ans :B

40. Vertical partitions providing strength and compartmentation on a ship are called . . .

(A) decks.
(B) bulkheads.
(C) joiner work.
(D) walls.

Ans :B

41. On a ship, the keel is the primary strength member of the lower hull form and is laid in which direction?

(A) transverse
(B) diagonal
(C) longitudinal
(D) vertical

Ans :C

42. With regards to the load line marks, the reason for the placement of mark “WNA” is . . .

(A) More severe weather is expected in the North Atlantic in winter.
(B) More freeboard is required in the North Atlantic in winter.
(C) More draft is allowed in the North Atlantic in winter.
(D) all of the above

Ans :A

43. If a cup of oil is spilled during bunkering and causes a sheen upon the water it . . .

(A) must be reported to the Port authorities.
(B) must be reported to the designated authority for pollution reporting in the area.
(C) need not be reported since the spill was less than 250 barrels.
(D) must be reported to the Flag State.

Ans :B

44. As a precaution against oil spills when topping off fuel tanks, you should . . .

(A) close the deck filling valve to reduce the pumping rate.
(B) close all tank vents to prevent overflow.
(C) fill the tank to the bottom of the expansion trunk.
(D) notify the shore pumping station to reduce the pumping rate as tanks near full capacity.

Ans 😀

45. If a leak in a fueling hose coupling cannot be stopped by tightening the coupling joint, you should . . .

(A) reduce the pumping pressure to reduce the leakage rate.
(B) stop the fueling operation and correct the leak.
(C) spread absorbent material on deck beneath the leak in order to confine it.
(D) notify the local port authority of a potential oil spill.

Ans :B

46. According to the International Oil Pollution Prevention Regulations (MARPOL) and safe tanker practices, if a cargo hose shows a small leak in its fabric, you may transfer oil after . . .

(A) the terminal foreman is notified and a deal is agreed upon.
(B) the hose is replaced.
(C) the hose leak is securely wrapped.
(D) a drip pan is placed under the leak.

Ans :B

47. Pieces of steel 10 meters length at a temperature is 0o C are being laid end to end. The linear co-efficient of expansion of this steel is 11 x 10-6/o C. If the temperature can rise up to a maximum of 50o C the space that must be left between the adjacent steel pieces is . . .

(A) 2.75mm
(B) 5.50mm
(C) 5.50m
(D) 11.00mm

Ans :B

48. A platinum wire can be sealed through glass but a brass one cannot be sealed because . . .

(A) platinum has greater density than brass.
(B) platinum and glass have the same value of volume expansion.
(C) platinum is an element while brass is an alloy.
(D) platinum does not rust .

Ans :B

49. The ratio of the densities of the two bodies is 3:4 and specific heat in the ratio 4:3. The ratio of their thermal capacities per unit volume is

(A) 9:16
(B) 2:1
(C) 16:9
(D) 1:1

Ans :A

50. 80 gm of water at 30o C are poured on a large block of ice at 0o C. The mass of the ice that melts is . . .

(A) 1600 gm
(B) 30 gm
(C) 150 gm
(D) 8 gm

Ans :B

51. A solid ball of metal has a spherical cavity inside it. The ball is heated. The volume of cavity will . . .

(A) decrease
(B) increase
(C) remain unchanged
(D) have its shape unchanged

Ans :A