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MEK exit exam questions and answers — Set 1 — Marine Engineering Knowledge

Set 1 of the Marine Engineering Knowledge (MEK) exit exam bank — 30 of 298 questions, with the correct option marked and a one-line explanation for every one. Read it end to end, jump to a single set, or search it — then sit the same bank as a timed paper. The real DG Shipping exit exam is 30 marks with 15 to pass.

These are the bank's original groupings. Practising deals the whole bank out again every time you reshuffle, so a practice “Set 3” is a different 30 questions each time — the set numbers below are the source file's, and are only used here so the key stays navigable. Options are listed in their original order with fixed letters; when you practise, those move too.

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Set 1 — 30 MEK exit exam questions with answers

1. Boiler is related to __________________

  • A. Storing Vegetables
  • B. Steam Generation
  • C. Steering
  • D. Human waste
Answer: B — Steam Generation
A boiler is a crucial piece of equipment onboard a ship responsible for generating steam. This steam is utilized for various purposes, including propulsion in steam-powered vessels and for heating systems.

2. Which of the following is bottom most part of a diesel engine?

  • A. Piston
  • B. Turbo charger
  • C. Connecting Rod
  • D. Exhaust valve
Answer: C — Connecting Rod
The connecting rod is positioned between the piston and the crankshaft. It is the bottom-most component among the choices provided that is directly involved in transmitting the linear motion of the piston to the rotating motion of the crankshaft.

3. Main Engine is part of the _________________ system

  • A. Electrical
  • B. Propulsion
  • C. Bilge
  • D. Ballast
Answer: B — Propulsion
The main engine is the primary source of power for a ship's movement, providing the necessary force to turn the propeller. Therefore, it is an integral part of the propulsion system.

4. Domestic Fridge is related to __________________.

  • A. Human waste
  • B. Storing Vegetables
  • C. Steering
  • D. Starting of Main Engine
Answer: B — Storing Vegetables
A domestic refrigerator onboard is used for the primary purpose of storing perishable items like vegetables, ensuring their freshness. It is a component of the ship's provisions and galley facilities.

5. Which of the following is top most part of a diesel engine?

  • A. crankcase door
  • B. crank shaft
  • C. cylinder head
  • D. piston
Answer: C — cylinder head
The cylinder head is the topmost component of a diesel engine cylinder, sealing the combustion chamber and housing the valves and injectors. It sits above the piston and cylinder liner.

6. Which of the following is lower most part of a diesel engine?

  • A. exhaust valve
  • B. bed plate
  • C. piston
  • D. turbo charger
Answer: B — bed plate
The bed plate forms the base of the diesel engine structure, supporting the crankshaft and carrying the main engine load. It is the lowest structural part of the engine assembly.

7. Which of the following is within the engine room?

  • A. cargo pump room
  • B. purifiers room
  • C. CO2 Room
  • D. paint storage room
Answer: B — purifiers room
The purifiers room (or centrifuge room) is dedicated to housing the machinery used for purifying fuel and lubricating oils, essential for the operation of the main engine and auxiliary machinery. This room is typically located within the engine room complex.

8. Which of the following is not within the engine room?

  • A. fresh water generator
  • B. fire pump
  • C. fridge room
  • D. refrigeration machinery
Answer: C — fridge room
The fridge room, used for storing provisions, is typically located in the galley or on deck, not within the engine room where machinery operates. The fresh water generator, fire pump, and refrigeration machinery are all essential engine room equipment.

9. Which of the following is job of an engine room rating?

  • A. report to bridge about engine condition
  • B. assist in maintenance work
  • C. overhaul air compressor
  • D. start and stop engine
Answer: B — assist in maintenance work
An engine room rating's primary duties include assisting in watchkeeping, performing routine maintenance under supervision, and carrying out specific tasks assigned by engineers. Starting and stopping the main engine, overhauling components, or reporting directly to the bridge are generally not their responsibilities.

10. Sewage Treatment Plant is related to __________________.

  • A. Starting of Main Engine
  • B. Steering
  • C. Storing Vegetables
  • D. Human waste
Answer: D — Human waste
The Sewage Treatment Plant (STP) is specifically designed to process human waste generated by the crew and passengers, treating it to meet environmental discharge standards as per MARPOL regulations. It is unrelated to engine starting, steering, or food storage.

11. What is not a system

  • A. Main Engine
  • B. Air compressor
  • C. Purifier
  • D. Boiler
Answer: A — Main Engine
The main engine is a complete functional unit that propels the ship. The boiler, purifier, and air compressor are individual systems or machines that are often part of the ship's overall engineering setup, but the main engine itself is the primary propulsion machine.

12. A "BOLT" has

  • A. Thread at both ends
  • B. Hexagonal head and threads at other end
  • C. Double pitch threads
  • D. Slotted head and threads at other end
Answer: B — Hexagonal head and threads at other end
A bolt is a fastener characterized by external screw threads and typically a hexagonal head, designed to be inserted through unthreaded holes in assembled parts and secured by a nut. It is not a threaded rod or a screw with a slotted head.

13. "Cuts" are caused by

  • A. Blunt chisels
  • B. Flat spanners
  • C. Sharp objects
  • D. Hammers
Answer: C — Sharp objects
Cuts, abrasions, and lacerations are typically caused by sharp objects such as knives, burrs on metal, or broken glass. While hammers and blunt chisels can cause blunt force trauma, they are not the direct cause of cuts.

14. For lifting a heavy load, you will use

  • A. Air Cylinder
  • B. Chain Block
  • C. Hydraulic Jack
  • D. Eye bolt
Answer: B — Chain Block
A chain block is a mechanical device used for lifting heavy loads, consisting of a chain and pulley system. While an eye bolt can be used for lifting, it's a component, and a hydraulic jack lifts by fluid pressure; a chain block is the general tool for heavy lifting.

15. A "STUD" has

  • A. Double pitch threads
  • B. Thread at both ends
  • C. Threads at one end with a slot at the other end
  • D. Hexagonal head and thread at the other end
Answer: B — Thread at both ends
A stud is a threaded fastener that has threads on both ends and no head, used for connecting two components where nuts are typically threaded onto both ends. It differs from a bolt, which has a head and threads at one end for a nut.

16. Which of this is not fitted on the cylinder head of a diesel engine

  • A. turbo charger
  • B. exhaust valve
  • C. starting valve
  • D. indicator valve
Answer: A — turbo charger
A turbocharger is an exhaust gas-driven turbine that forces more air into the engine cylinders to increase power and efficiency. It is not a component directly fitted on the cylinder head itself, unlike the exhaust valve, starting valve, and indicator valve.

17. Regarding practical watchkeeping and logbook documentation in Marine Engineering Knowledge, what is the mandatory safety standard required under STCW Code Table A-III/4?

  • A. Applicable only when vessel is anchored
  • B. Non-mandatory recommendation
  • C. Optional compliance based on crew discretion
  • D. Full compliance with approved STCW safety procedures and SMS protocols
Answer: D — Full compliance with approved STCW safety procedures and SMS protocols
STCW Code Section A-III/4 requires strict adherence to approved safety protocols for Marine Engineering Knowledge.

18. What is the main function of the lubricating oil crosshead bearings in a two-stroke marine diesel engine?

  • A. Provide high-pressure oil film to withstand heavy piston combustion loads
  • B. Drive the camshaft chain
  • C. Cool the engine flywheel
  • D. Lubricate the turbocharger shaft
Answer: A — Provide high-pressure oil film to withstand heavy piston combustion loads
Crosshead bearings require high-pressure oil to support oscillating combustion forces.

19. What component in a marine diesel engine converts reciprocating piston motion into rotary crankshaft motion?

  • A. Connecting Rod
  • B. Piston Rod
  • C. Crosshead Guide
  • D. Camshaft
Answer: A — Connecting Rod
The connecting rod links the crosshead/piston to the crankshaft pin, converting motion.

20. What is the purpose of the scavenger air receiver in a two-stroke marine diesel engine?

  • A. Cool jacket cooling water
  • B. Collect waste exhaust carbon
  • C. Store starting air at 30 bar
  • D. Accumulate pressurized air from the turbocharger to scavenge exhaust gases from cylinders
Answer: D — Accumulate pressurized air from the turbocharger to scavenge exhaust gases from cylinders
Scavenge receivers supply fresh air to clear burnt gases and recharge cylinders.

21. What instrument measures exhaust gas temperatures at individual cylinder outlets?

  • A. Tachometer
  • B. Pyrometer / Thermocouple
  • C. Manometer
  • D. Hydrometer
Answer: B — Pyrometer / Thermocouple
Pyrometers monitor combustion quality and load distribution across cylinders.

22. What is the purpose of a crankcase explosion relief valve on a marine engine?

  • A. Vent oil vapor continuously to deck
  • B. Relieve internal crankcase overpressure safely and prevent flame return into engine room
  • C. Allow inspection of main bearings
  • D. Drain waste oil to bilge
Answer: B — Relieve internal crankcase overpressure safely and prevent flame return into engine room
Relief valves release pressure during oil mist ignition and seal shut to stop air ingress.

23. What component removes solid impurities and water from heavy fuel oil before combustion?

  • A. Fuel heater
  • B. Viscosimeter
  • C. Duplex mesh strainer
  • D. Centrifugal Fuel Purifier / Separator
Answer: D — Centrifugal Fuel Purifier / Separator
Centrifugal purifiers spin at high speed to separate water and heavy solids from HFO.

24. What is the function of the main engine thrust block?

  • A. Prevent propeller shaft rotation
  • B. Transfer propeller axial thrust force from the shafting to the ship's hull structure
  • C. Cool stern tube bearings
  • D. Support generator weight
Answer: B — Transfer propeller axial thrust force from the shafting to the ship's hull structure
Thrust blocks absorb forward/astern propeller thrust and push the vessel's hull.

25. Why is jacket cooling water kept treated with chemical inhibitors in marine diesel engines?

  • A. Lubricate water pump impellers
  • B. Reduce water density
  • C. Prevent corrosion, cavitation, and scale formation inside cooling water passages
  • D. Increase water boiling point to 300°C
Answer: C — Prevent corrosion, cavitation, and scale formation inside cooling water passages
Chemical treatment prevents liner pitting, scale buildup, and heat transfer degradation.

26. What is the function of the economizer fitted in a ship's main engine exhaust boiler system?

  • A. Increase turbocharger speed
  • B. Burn HFO waste sludges
  • C. Generate auxiliary steam by absorbing waste heat from engine exhaust gases
  • D. Cool exhaust gas before stack discharge
Answer: C — Generate auxiliary steam by absorbing waste heat from engine exhaust gases
Economizers recover waste heat from exhaust gases to generate service steam at sea.

27. What safety device prevents starting air from entering an engine cylinder when the piston is in motion?

  • A. Cylinder relief valve
  • B. Fuel injector needle
  • C. Starting air distributor / control valve
  • D. Exhaust valve rotator
Answer: C — Starting air distributor / control valve
Air distributors time air delivery strictly during the starting stroke sequence.

28. What is the function of an oily water separator (OWS) bilge alarm (15 ppm monitor)?

  • A. Measure fuel viscosity
  • B. Check bilge well level
  • C. Continuously monitor discharge water purity and stop overboard valve if oil exceeds 15 ppm
  • D. Pump bilge water out faster
Answer: C — Continuously monitor discharge water purity and stop overboard valve if oil exceeds 15 ppm
The 15 ppm monitor ensures compliance with MARPOL Annex I by auto-stopping illegal discharge.

29. What causes thermal surging in a marine engine turbocharger?

  • A. Excessive cooling water temperature
  • B. High fuel viscosity
  • C. Low engine lube oil pressure
  • D. Breakdown of smooth airflow through compressor due to sudden engine load changes or fouled grid
Answer: D — Breakdown of smooth airflow through compressor due to sudden engine load changes or fouled grid
Surging occurs when compressor backpressure exceeds aerodynamic delivery pressure.

30. What is the main advantage of using a variable pitch propeller (CPP) on merchant vessels?

  • A. Allows continuous engine operation at optimal RPM while controlling vessel speed via blade pitch
  • B. Requires no hydraulic oil
  • C. Reduces hull resistance to zero
  • D. Eliminates need for stern tube bearings
Answer: A — Allows continuous engine operation at optimal RPM while controlling vessel speed via blade pitch
CPP allows rapid maneuvering without reversing main engine rotation direction.

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