MEO Class 4 Exam Questions and Answers 2020 – Section 4

MEO Class 4 Exam Questions and Answers 2020 – Section 4

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1. Fabric type packing, such as flax or hemp, is best suited for _____________.

  • low temperature use
  • high-temperature use
  • packing valves with badly grooved stems

2. Which of the listed problems is occurring if a coil type high-pressure evaporator constantly requires an increase in the coil steam pressure in order to maintain capacity?

  • The brine density is improper.
  • Heat transfer surfaces are being layered with scale.
  • Shell vapor pressure is constantly decreasing.

3. The terms rough, coarse, bastard, second cut, smooth, and dead smooth refer to the ________.

  • The shape of the file
  •  coarseness of the file teeth
  • size of the file
  • cuts of the file

 4. A pump is defined as “a device that _____________.”

  • produces pressure
  • imparts energy to a fluid to move it from level “A” to level “B”
  • creates a vacuum to move a liquid in all installations
  • is to develop a pressure differential

5. Restrictions occurring in the small orifices of pneumatic control system components can be caused by

  • moisture in the compressed air supply
  • excessive dryness in the compressed air supply
  • pressure surging in the compressed air receiver
  • insufficient lubrication of the system components

6. The principal purpose of subcooling liquid refrigerant prior to its entering the expansion valve is to

  • increase the refrigerating effect by decreasing the amount of flash gas
  • allow the refrigerant to enter the throttling-device in a saturated condition
  • increase the refrigerating effect by increasing the amount of flash gas
  • minimize the temperature drop of the liquid as it passes through the solenoid valve to the outlet side

7. If a bilge pump is able to develop vacuum, but is unable to sufficiently pump-out the bilges, you would check for ________.

  • the circuit breaker
  • for leaks in the suction piping
  • the relief valve is not properly seated
  • the suction strainer

 8. A first stage unloader installed in a low-pressure air compressor is unable to completely retract. This will result in ____

  • overheating of the discharge valve
  • loss of moisture in the air charge in the receiver
  • frequent lifting of the intercooler relief valve
  • an abnormally low intercooler pressure

 9. The heat removed from the refrigerant in the condenser of a refrigeration plant is the

  • latent heat of expansion
  • the sensible heat of condensation
  • heat of compression
  • all of the above

 10. Excessive leakage and premature failure of valve packing is a result of ____________.

  • opening a valve too quickly
  • jamming a valve in the closed position
  • low-pressure fluid flow through the pipeline
  • a scored valve stem

11. The amount of fuel oil atomized by a return flow oil burner is directly controlled by the 

  • header supply valve
  • burner root valve
  • oil micrometer valve
  • fuel oil back pressure

12. Fuses are rated in _

  • voltage
  • amperage
  • interrupting capacity
  • all the above

 13. When there is excessive ingress of water in the engine room onboard causing dangerous levels of bilge water,

  • Start oily water separator and pump overboard
  • Start General service pumps and pumps bilges overboard 
  • Use bilge injection valve and pump bilges overboard
  • None of the above

14. If a radial piston hydraulic pump fails to deliver rated fluid volume, the cause can be _______________.

  • contaminated fluid
  • pitted thrust rings
  • worn pintle bearings
  • obstructed suctions passage

 15. A fluctuating and unsteady vacuum in an evaporator may be caused by _____________.

  • wet steam entering the air ejector nozzle
  • pinhole leaks in the evaporator tube nests
  • rapid scaling on the evaporator tube nests
  • high water levels in the last effect

 16. A generator has been exposed to water and is being checked for its safe operation. Therefore, it is necessary to _______________.

  • check for shorted coils with an explosimeter.
  • take moisture readings with a hydrometer
  • test insulation values with a megger
  • ground the commutator, or slip rings and run it at half load

 17. If the pointer fails to return to zero when a megger is disconnected, the_____________.

  • pointer is stuck
  • hairsprings are burned out
  • megger is out of calibration
  • megger is operating normally

 18. When replacing ball bearings on an electric motor shaft, you should _____________.

  • tap the outer race with a mallet
  • apply even pressure to the outer race
  • apply even force to the inner race
  • apply pressure evenly to both the inner and outer races

 19. The zipper of an immersion suit should be lubricated with _____________.

  • paraffin
  • oil
  • graphite
  • vegetable oil

20. An insulation resistance test is performed on a particular piece of electric equipment.  In addition to the resistance reading, what information listed below should be entered in the electrical log?

  • The maximum allowable operating temperature of the machine.
  • The temperature of the machine at the time the resistance reading was taken.
  • The normal temperature rise of the machine.
  • The complete nameplate data from the resistance test instrument used to obtain the reading.

21. When removing the cap from a sounding tube on a MODU, the sound of air escaping indicates.

  • the tank is full
  • the tank may be partially flooded
  • the tank level has dropped
  • the tank is completely flooded

 22. A solid stream of water might be useful in fighting a burning oil fire on the deck when it is used ____________.

  • to wash burning oil over the side
  • to provide cooling for the firefighters
  • in conjunction with chemical foam
  • to cool the main deck

 23. The burner assembly on an automatically fired auxiliary boiler fitted with variable capacity, pressure atomizing burners, maintains steam pressure by 

  • cycling on and off
  • changing fuel oil return pressure
  • changing the speed of a rotary cup
  • Varying air pressure supplied to the nozzle

24. Galvanic action which of the following is false. A. only one metal does not initiate corrosion

  • Two metal with electrolyte will not initiate corrosion

 25. In Stern tube, aft of FOREWARD SEAL is leaking then 

  • forward tank oil level increase
  • drop in header tank level

 26. While starting a hydraulic anchor windlass, you observe that hydraulic pressure does not develop in spite of the proper operation of the electric drive motor. Which of the following actions should you take FIRST to restore pressure?

  • Make certain that the hydraulic reservoir is filled to the proper level.
  • Inspect the disc brake on the electric motor for proper operation.
  • Check the electric motor for an open overload relay contact.
  • Check for full voltage supply to the electric motor.

 27. A primary element used with flow measurement devices highly suitable for liquids containing solids in suspension, is a ____________.

  • concentric orifice
  • convergent nozzle
  • venturi tube
  • pilot tube

 28. Prior to a major overhaul of the main engine on board, the engine room crane is tested by

  • Operating the crane through the normal range
  • Testing of the crane with two sample abnormal conditions
  •  Inspection of the crane hook and other safety arrangements
  • Stress testing of crane wire with peak loads

 29. Water carryover from the boiler onboard through the steam causes

  • Erosion of the steam plant machinery
  • Low-water level inside the boiler
  • A build-up of deposits on the steam plant machinery
  • None of the above

 30. A diffuser is provided at the end of a mechanical atomizer in the boiler onboard

  • To prevent blowback of the flame 
  • To mix the air and fuel properly
  • To prevent blow out of the flame
  • To eject the excess fumes from the atomizer

 31. Short cycling of a fridge compressor can occur in which of the following cases?

  • Air ingress into the system
  • A leaking solenoid valve
  • High cooling water temperature going to the condenser
  • Excessive refrigerant charge

 32. Steam Stop valve is eased of its seat during boiler start-up from cold

  • To allow thermal expansion of parts
  • To allow steam flow during start-up
  • To prevent water hammer
  • All of the above

33. Duty of standby person at the entrance of the enclosed compartment during enclosed space entry is

  • To alert others in case of untoward emergency
  • To provide first aid to the injured person
  • To assist for the work carried out in the enclosed compartment
  • All of the above.

34. Which of the following statements about the design of D- type boilers, is false?

  • The heavier water in the top drum flows back to the bottom drum through the down- comers outside the furnace
  • Inside the furnace the water is heated up in the risers
  • The upper drum is the steam/water drum and the lower one is the water drum.
  • The feedwater is pumped into the lower drum

35. If the watchkeeping engineer encounters the Main Engine Slow down alarm he should__

  • Immediately cancel the slowdown in the control panel
  • If navigation circumstances permit, after consulting the chief engineer he should tell the bridge to stop the engine, investigate the fault, rectify it in consultation with senior engineers and then prepare for restarting the engine
  • He should raise the engineer’s alarm and wait for all engineers to reach the engine room
  • He need not take any action and wait for the alarm to resolve on its own and then cancel the slowdown

36. Which of the following types of coatings used in tanks of a chemical carrier provides comprehensive protection against most solvents?

  • Epoxy coatings
  • Polyurethane coatings
  • Zinc silicate
  • Phenolic resins

37. Presence of catalytic fines in fuel oil is significant to engineers on board because_

  • Catalytic fines tend to impair the proper operation of purifiers
  • Catalytic fines lead to abrasive wear in liners, piston rings and fuel injection equipment 
  • Catalytic fines necessitate an increase in injection temperature
  • Catalytic fines necessitate an increase in storage temperature

38. A partial opening of which of the following kinds of valves can lead to wire -drawing of its seat?

  • Globe Valve
  • Butterfly valve
  • Gate Valve
  • Full bore angle valve

39. Which of the following types of steam-traps use the pressure energy of the steam to close the outlet?

  • Thermostatic trap
  • Thermodynamic trap
  • Mechanical trap
  • Vacuum trap

40. Sequential starting of machinery after a blackout in the engine room is necessary

  • To prevent overload of Generators
  • To quickly restore the failed power supply in order
  • To prevent damage to machinery which has been switched off
  • All of the above

41. Salinity of distilled water produced from freshwater generator onboard depends on 

  • Amount of feed set in freshwater production
  • Amount of saltwater leaking from condenser if any
  • Temperature of the seawater used
  • The efficiency of brine ejector from the evaporator shell

42. Which of the following is the material used for manufacturing tube plates of a shell and tube type heat exchanger?

  • Cupro-nickel
  • Aluminum Brass
  • Admiralty Brass
  • Gunmetal

43. How is the water circulated between water and steam drums in a water tube D- type boiler? 

  • By the boiler feedwater pump
  • By a circulating pump outside the boiler
  • Due to the difference in densities of water and steam 
  • None of the above

44. The seating material for perfectly sealing type Ball valves is usually made up of 

  • Rubber 
  • PTFE or Nylon 
  • Rubber reinforced with steel wire 
  • Stainless steel

 45. Air is removed from refrigeration system by (1) ________ at receiver after (2) ________
(3) ___ Gas in receiver.


46. Water leaking from a pump packing gland is kept away from the bearing housing by the use of

  • shaft sleeves
  • lantern rings
  • water defectors
  • water seals

47. Which of the following conditions should be used to support the need to change the lube oil when there has been an increase in the neutralization number?

  • A decrease in the viscosity of the oil
  • An increase in the viscosity of the oil
  • A change in the cloud point
  • A change in the floc point

48. The purpose of bilge keels as an example is to reduce the amplitude of roll. What arrangements need to be made on a ship to achieve the following:

  • lower the center of gravity of the ship
  • reduce pitching
  • reduce yawing

49. A casing drain is provided for axial piston and bent axis variable stroke pumps to___________.

  • vent off any accumulated air from the system
  • drain off any accumulated water from the pump casing prior to its being started
  • assist the complete removal of hydraulic oil from the system prior to opening for major or minor repairs
  • prevent damage due to agitation and overheating of oil accumulated in the casing as a result of minor internal leakage

50. Increasing the speed of a rotary pump above its rated speed will result in most of the following conditions to occur?

  • Increased suction
  • Increased clearances
  • Vibrations
  • slippage

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