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AIGF exit exam questions and answers — Set 6

Set 6 of the Advanced Training for Ships subject to the IGF Code (AIGF) exit exam bank — 30 of 342 questions, with the correct option marked, and 29 of them also carry a one-line explanation. 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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30 of 30 shown · Set 6

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Set 6 — 30 AIGF exit exam questions with answers

1. Derating is an engine for reduction of the vessels maximum speed to increase the efficiency by limiting the __________

  • A. potential power output
  • B. None of the above
  • C. kinetic power output
  • D. total output
Answer: A — potential power output
Derating an engine reduces maximum service power output and matches turbocharging and injection timing to optimal lower load profiles for maximum fuel efficiency.

2. Derating is an engine for ________ of the vessels maximum speed to increase the efficiency by limiting the potential power output

  • A. reduction
  • B. increase
  • C. production
  • D. addition
Answer: A — reduction
Derating limits the potential maximum power output of the propulsion engine to operate at peak thermodynamic efficiency during slow steaming.

3. Derating is an engine for reduction of the vessels _______ speed to increase the efficiency by limiting the potential power output

  • A. normal
  • B. minimum
  • C. None of the above
  • D. maximum
Answer: B — minimum
Engine derating re-optimizes the engine for lower continuous operational speeds to reduce specific fuel consumption and carbon intensity.

4. What is meant by engine performance optimization?

  • A. automatic increase of engine efficiency
  • B. mechanical increase of engine efficiency
  • C. non automatic increase of engine efficiency
  • D. manual increase of engine efficiency
Answer: A — automatic increase of engine efficiency
Engine performance optimization automatically adjusts fuel injection timing, exhaust valve timing, and scavenge air pressure to maintain peak firing pressures across all loads.

5. ______ requires thermal energy from the exhaust gas and convert it into electrical energy

  • A. None of the above
  • B. recirculation recovery system
  • C. manual heat recovery system
  • D. waste heat recovery system
Answer: D — waste heat recovery system
Waste Heat Recovery Systems (WHRS) utilize exhaust gas economizers, steam turbines, and power turbines to convert waste thermal energy into electrical power.

6. Waste heat recovery system requires _______ energy from the exhaust gas and convert it into electrical energy

  • A. kinetic
  • B. potential
  • C. thermal
  • D. dynamic
Answer: C — thermal
WHRS extracts residual thermal energy from high-temperature engine exhaust gases to drive a steam turbine-generator set.

7. Waste heat recovery system requires thermal energy from the _______ gas and convert it into electrical energy

  • A. inert
  • B. exhaust
  • C. energise
  • D. None of the above
Answer: B — exhaust
Main engine exhaust gas holds significant waste thermal energy that can be recovered by combined steam and gas turbine systems.

8. Turbo charger refitting increases efficieny and reduce emissions of _______ engine

  • A. main
  • B. side
  • C. left
  • D. right
Answer: A — main
Retrofitting advanced turbochargers on main propulsion engines optimizes scavenge air mass flow, improves combustion efficiency, and lowers emissions.

9. Turbo charger refitting _______ efficieny and reduce emissions of main engine

  • A. balance
  • B. equalize
  • C. decrease
  • D. increases
Answer: D — increases
Turbocharger upgrading increases engine thermodynamic efficiency and lowers specific emissions across intermediate engine load ranges.

10. Upgrading Turbo charger to ________ will increase efficiency

  • A. VTA technology
  • B. ATV technology
  • C. to A technology
  • D. Vat tehnology
Answer: A — VTA technology
Variable Turbine Area (VTA) technology incorporates adjustable nozzle vanes to optimize exhaust gas velocity and scavenge air pressure at all engine loads.

11. Upgrading _______ to VTA technology will increase efficiency

  • A. exhaust boiler
  • B. None of the above
  • C. propulsion shaft
  • D. Turbo charger
Answer: D — Turbo charger
Upgrading standard turbochargers with Variable Turbine Area (VTA) technology optimizes scavenge pressure and enhances low-load combustion efficiency.

12. Upgrading Turbo charger to VTA technology will _______ efficiency

  • A. equalize
  • B. decrease
  • C. increase
  • D. balance
Answer: C — increase
VTA turbochargers increase part-load fuel efficiency and engine responsiveness by adjusting nozzle blade angles to match exhaust mass flow.

13. _______ efficiency can be increased by utilising existing turbo charger with the latest man disel turbo charger

  • A. Motor
  • B. propeller
  • C. Engine
  • D. All the above
Answer: C — Engine
Propulsion engine efficiency is maximized by matching modern turbocharging systems with optimized fuel injection and electronic valve control.

14. What is mean by jet assist systems?

  • A. None of the above
  • B. giving compressed air from an external source to aid compresser will acceleration in turbo chargers
  • C. to give compressed air service to auxiliary engines
  • D. to give compressed air supply for cleaning sewage treatment plant
Answer: B — giving compressed air from an external source to aid compresser will acceleration in turbo chargers
Jet assist systems inject compressed air into the turbocharger compressor casing to accelerate the rotor and eliminate turbo lag during rapid engine acceleration.

15. LNG engines reduces CO2 emission by how much ?

  • A. 15-20%
  • B. 45-50%
  • C. 25-30%
  • D. 35-40%
Answer: C — 25-30%
Natural gas fueled dual-fuel engines achieve a 20% to 25-30% reduction in carbon dioxide (CO2) emissions compared to standard heavy fuel oil.

16. LNG has fuel reduces Nox emission by about

  • A. 90%
  • B. 100%
  • C. 91%
  • D. 92%
Answer: A — 90%
Low-pressure dual-fuel gas engines (Otto cycle) reduce nitrogen oxide (NOx) emissions by up to 85-90%, complying inherently with IMO Tier III limits.

17. LNG has fuel reduces sox emission by about

  • A. 92%
  • B. 91%
  • C. 90%
  • D. almost negligible
Answer: D — almost negligible
Because natural gas contains virtually no sulfur, SOx emissions from LNG-fueled engines are almost zero (negligible).

18. Advantages of VTA turbo charger

  • A. an alternator is attached to a blower end
  • B. reduces the fuel consumption
  • C. to eliminates the need for auxiliary blower
  • D. All the above
Answer: A — an alternator is attached to a blower end

19. Turbo charger works efficiently in _________

  • A. entire load of the engine
  • B. start of the engine
  • C. None of the above
  • D. partial load of the engine
Answer: A — entire load of the engine
Modern turbochargers are designed to operate efficiently across the entire engine load envelope from idle to 100% MCR.

20. The low pressure XDF tecnhnology concept is based on the __________

  • A. exhaust gas principle
  • B. None of the above
  • C. sewage plant principle
  • D. lean burn principle
Answer: D — lean burn principle
WinGD low-pressure X-DF dual-fuel engines operate on the lean-burn Otto cycle, premixing low-pressure gas with scavenge air before pilot fuel ignition.

21. XDF engine provide which benefit

  • A. low pressure gas supply
  • B. pilot fuel quantity below 1%
  • C. All the above
  • D. DF engine can be operated on gas from ideal
Answer: C — All the above
Low-pressure X-DF technology offers IMO Tier III compliance without exhaust gas aftertreatment, lower gas supply pressure (<16 bar), and reduced capital costs.

22. _______ engine provide pilot fuel quantity below 1%

  • A. YDF
  • B. XTF
  • C. GDF
  • D. XDF
Answer: D — XDF
WinGD X-DF engines require very small amounts of pilot diesel fuel (less than 1% of total energy at high loads) to ignite the lean gas-air mixture.

23. Particulate matters emissions reduced to almost zero in which technology

  • A. high pressure XDF
  • B. low pressure YDF
  • C. low pressure XDF
  • D. high pressure YDF
Answer: C — low pressure XDF
Particulate matter (PM) and soot emissions are reduced to near zero in low-pressure lean-burn gas engines due to clean methane combustion.

24. Which type of engine does not need exhaust gas treatment system

  • A. GDF engines
  • B. ZDF engines
  • C. XDF engines
  • D. YDF engines
Answer: C — XDF engines
Low-pressure dual-fuel Otto cycle engines meet IMO Tier III NOx limits in gas mode without needing Selective Catalytic Reduction (SCR) or Exhaust Gas Recirculation (EGR).

25. What are the advantages of Mr. diesel process man engine

  • A. All the above
  • B. diesel process maintain
  • C. load response unchanged
  • D. low preignition or no knocking
Answer: A — All the above
MAN ME-GI engines utilize high-pressure gas injection on the Diesel cycle, delivering high thermal efficiency, zero knock risk, and minimal methane slip.

26. Mr otto process LNG engine has got following advantage

  • A. All the above
  • B. reduction in nox emissions
  • C. low pressure gas injection
  • D. gas mixture is important
Answer: A — All the above
Otto-cycle low-pressure gas engines operate with low gas supply pressures (<10-16 bar), simpler fuel gas supply systems, and low Tier III NOx emissions.

27. Derating of the propulsion engine can be achieved by

  • A. All the above
  • B. modifying fuel valves
  • C. simming between crosscuts and piston rods
  • D. rematching the turbo chargers
Answer: A — All the above
Engine derating can be achieved by installing smaller turbocharger nozzle rings, adjusting fuel injection profiles, and modifying electronic control parameters.

28. Disadvantage of rerating a engine is

  • A. this may require additional denox measures
  • B. increased specific fuel oil consumption
  • C. this may require additional sox measures
  • D. None of the above
Answer: A — this may require additional denox measures
Rerating or modifying engine combustion for higher maximum pressure without proper tuning may elevate peak combustion temperatures, potentially increasing NOx formation.

29. Disadvantage of hybrid turbo charger is

  • A. doesn’t require lubrication
  • B. heat generated is less
  • C. doesn’t require cooling
  • D. heat generated is more
Answer: D — heat generated is more
Disadvantages of hybrid turbochargers include increased mechanical complexity, additional electrical cooling requirements, and higher capital expense.

30. Advantage of hybrid turbo charger is

  • A. it recovers cold energy
  • B. it is doing nothing
  • C. it decreses the power of the main engine
  • D. it recovers hot energy
Answer: D — it recovers hot energy
The main advantage of a hybrid turbocharger is the recovery of waste exhaust energy to generate electrical power, reducing auxiliary diesel generator fuel consumption.

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