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BIGF exit exam questions and answers — Set 6

Set 6 of the Basic Training for Ships subject to the IGF Code (BIGF) exit exam bank — 30 of 181 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 6 — 30 BIGF exit exam questions with answers

1. For fuel tanks fitted with PRVs, which can be set at more than one set pressure, What is provided for each set pressure?

  • A. safe-pressure alarms
  • B. medium-pressure alarms
  • C. high-pressure alarms
  • D. low-pressure alarms
Answer: B — medium-pressure alarms
When fuel tanks are fitted with pressure relief valves (PRVs) with dual or multiple set pressures, appropriate pressure alarms and interlocks are provided for each selectable setting.

2. For each main gas supply line entering an ESD protected machinery space, and each gas supply line to high pressure installations

  • A. Means shall be provided for rapid detection of a rupture in the gas line in the engine-room.
  • B. The pipelines should be always double walled
  • C. In case of gas leakage an automatic alarm should actuate
  • D. Due to redundancy there should not be any unacceptable loss of power
Answer: A — Means shall be provided for rapid detection of a rupture in the gas line in the engine-room.
For main gas supply lines entering ESD-protected machinery spaces, automated monitoring must provide rapid detection of any pressure drop or line rupture to trigger instantaneous fuel trip valves.

3. What is the critical temperature (deg C) of vinyl chloride?

  • A. -6592.0
  • B. 158.4
  • C. -6214.0
  • D. -6524.0
Answer: B — 158.4
The critical temperature of Vinyl Chloride Monomer (VCM) is 158.4°C, above which it cannot exist as a separate liquid phase.

4. What is the critical temperature (deg C) of ethylene oxide?

  • A. 195.7
  • B. -6249.0
  • C. -5486.0
  • D. -5947.0
Answer: A — 195.7
The critical temperature of Ethylene Oxide is 195.7°C, with a critical pressure of approximately 71.9 bar.

5. What is the critical temperature (deg C) of propylene oxide?

  • A. -6593.0
  • B. 209.1
  • C. -8529.0
  • D. -6219.0
Answer: B — 209.1
The critical temperature of Propylene Oxide is 209.1°C, with a critical pressure of approximately 49.2 bar.

6. What is the critical temperature (deg C) of ammonia?

  • A. -5627.0
  • B. 132.4
  • C. -5649.0
  • D. -6597.0
Answer: B — 132.4
The critical temperature of Anhydrous Ammonia (NH3) is 132.4°C, with a critical pressure of 112.8 bar.

7. What is the critical temperature (deg C) of Chlorine?

  • A. -9657.0
  • B. -2546.0
  • C. -5698.0
  • D. 144.0
Answer: D — 144.0
The critical temperature of Chlorine (Cl2) is 144.0°C, with a critical pressure of 77.1 bar.

8. What is the critical pressure (bars, absolute) of Methane?

  • A. 44.7
  • B. -2345.0
  • C. -6249.0
  • D. -5947.0
Answer: A — 44.7
The critical pressure of Methane (CH4) is 45.99 bar absolute (commonly referenced in maritime gas tables as 44.7 to 46.0 bar absolute).

9. What is the critical pressure (bars, absolute) of Ethane?

  • A. -7648.0
  • B. -5486.0
  • C. -8529.0
  • D. 48.9
Answer: D — 48.9
The critical pressure of Ethane (C2H6) is 48.8 bar absolute (approx. 48.9 bar absolute).

10. Which gas is considered as Fuel [in the context of this code] in liquid and compressed form

  • A. All the above
  • B. propane
  • C. Natural gas
  • D. i-Butane
Answer: A — All the above
Under the IGF Code, gases considered as fuel in liquid or compressed forms include natural gas (methane), LPG (propane/butane), ethane, and synthetic gas fuels.

11. In IGF Code, Which is called Fuel containment system

  • A. Any tank
  • B. Cargo tank
  • C. the transfer of liquid from land based
  • D. the arrangement for the storage of fuel including and connections
Answer: D — the arrangement for the storage of fuel including and connections
Under the IGF Code, the Fuel Containment System is the complete arrangement for storing fuel, including tank primary barriers, secondary barriers, insulation, and tank connection spaces.

12. In IGF Code, Independent tanks means

  • A. none of the above
  • B. both (a) and (b)
  • C. are not essential to the hull strength
  • D. self-supporting, do not form part of the ship's hull
Answer: B — both (a) and (b)
Independent tanks are self-supporting fuel containment structures that do not form part of the ship's hull and do not contribute to overall hull girder strength.

13. ____________is capable of being ignited.

  • A. Inflammable
  • B. Flammable
  • C. Absolute temperature
  • D. Absolute zero
Answer: B — Flammable
A substance is classified as flammable if it is capable of being ignited and burning in the presence of an oxidizer.

14. _________ is the range of gas concentrations in air between which the mixture is flammable.

  • A. Inflammable range
  • B. Flammable range
  • C. Pressure range
  • D. Temperature range
Answer: B — Flammable range
The flammable range (or explosive range) is the range of fuel gas concentrations in air (between LEL and UEL) within which combustion can occur upon ignition.

15. Flammable range is the range of concentrations between

  • A. lower flammable limit
  • B. upper flammablle limit
  • C. none of the above
  • D. both (a) and (b)
Answer: D — both (a) and (b)
The flammable range is defined by the interval between the Lower Flammable Limit (LFL/LEL) and the Upper Flammable Limit (UFL/UEL).

16. Flash point is the ________ temperature at which a liquid gives off sufficient vapour to form a flammable mixture with air near the surface of the liquid.

  • A. zero
  • B. lowest
  • C. highest
  • D. medium
Answer: B — lowest
The flash point is the lowest liquid temperature at which sufficient vapor is evolved to form an ignitable flammable mixture with air near the liquid surface.

17. Gas code are ______________carrying liquefied gases in bulk

  • A. equipment of ships
  • B. none of the above
  • C. both (a) and (b)
  • D. codes of construction
Answer: C — both (a) and (b)
The IMO Gas Codes (GC Code, IGC Code, IGF Code) provide international safety standards for ships carrying liquefied gases in bulk or using gases as fuel.

18. Gas codes are published by ____________

  • A. Indian Marine Organisation
  • B. International Marine Oraganisation
  • C. International Maritime Oraganisation
  • D. Indian Maritime Organisation
Answer: C — International Maritime Oraganisation
The International Gas Codes (IGC Code, IGF Code) are developed, updated, and published by the International Maritime Organization (IMO).

19. ___________ is within ship's cargo area which is designated as likely to contain flammable vapour

  • A. Gas dangerous zone
  • B. both (a) and (b)
  • C. none of the above
  • D. Gas dangerous space
Answer: B — both (a) and (b)
A hazardous area is a designated zone on board ship within which a flammable gas atmosphere is expected to be present in quantities requiring specialized electrical equipment and precautions.

20. What does gas free certificate certified for?

  • A. 21 percent nitrogen by volume
  • B. 21 percent carbon dioxide by volume
  • C. 21 percent hydrogen by volume
  • D. 21 percent oxygen by volume
Answer: D — 21 percent oxygen by volume
A standard Gas Free Certificate confirms that an enclosed space contains 20.9% to 21% oxygen by volume, 0% LEL of flammable vapors, and safe toxic gas limits.

21. When is gas free certificate issued?

  • A. considered safe for surrounding hot work
  • B. tank hs been suitably inerted
  • C. both (a) and (b)
  • D. none of the above
Answer: C — both (a) and (b)
A Gas Free Certificate is issued by a certified marine chemist or authorized safety officer prior to hot work or shipyard drydock operations.

22. What is Gas freeing?

  • A. All of the above
  • B. removal of inert gas from a tank
  • C. removal of flammable gas from a tank
  • D. removal of toxic gas from a tank
Answer: A — All of the above
Gas freeing is the process of displacing inert gas or cargo vapors from tanks and void spaces using fresh air until the atmosphere is non-toxic, non-flammable, and breathable.

23. What is latent heat of vaporization?

  • A. permitting the outward passage of gas
  • B. sufficiently free from chemical
  • C. sufficiently free from hydrocarbon gases
  • D. Quality of heat to change the state of a substance from liquid to vapour without change of temperature
Answer: D — Quality of heat to change the state of a substance from liquid to vapour without change of temperature
Latent heat of vaporization is the amount of heat energy required to transform a unit mass of liquid into vapor at its boiling point without any change in temperature.

24. In latent heat of vaporization, Quality of heat to change the state of a substance from ____________ without change of temperature

  • A. solid to liquid
  • B. solid to vapour
  • C. liquid to molecules
  • D. liquid to vapour
Answer: D — liquid to vapour
Latent heat of vaporization measures the thermal energy required to change a substance's physical phase from liquid to vapor at constant temperature and pressure.

25. What is Liquefied gas?

  • A. sufficiently free from hydrocarbon gases
  • B. liquid which has a saturated vapour pressure exceeding 2.8 bar absolute at 37.80C and certain other substances specified in the Gas Codes
  • C. Quality of heat to change the state of a substance from liquid to vapour without change of temperature
  • D. permitting the outward passage of gas
Answer: B — liquid which has a saturated vapour pressure exceeding 2.8 bar absolute at 37.80C and certain other substances specified in the Gas Codes
The IMO Gas Codes define a liquefied gas as any liquid having a saturated vapor pressure exceeding 2.8 bar absolute at a temperature of 37.8°C.

26. In Liquefied gas, a liquid which has a saturated vapour pressure exceeding ______ absolute at 37.80C and certain other substances specified in the Gas Codes.

  • A. 18 bar
  • B. 308 bar
  • C. 48 bar
  • D. 2.8 bar
Answer: D — 2.8 bar
Liquefied gases are legally defined by a saturated vapor pressure exceeding 2.8 bar absolute at 37.8°C under the IMO IGC and IGF Codes.

27. In Liquefied gas, a liquid which has a saturated vapour pressure exceeding 2.8 bar absolute at __________ and certain other substances specified in the Gas Codes.

  • A. none of the above
  • B. 0
  • C. 100
  • D. 37.80C
Answer: D — 37.80C
The standard reference temperature at which the 2.8 bar absolute vapor pressure threshold is measured under the IMO Gas Codes is 37.8°C (100°F).

28. In Liquefied gas, a liquid which has a saturated vapour pressure __________ 2.8 bar absolute at 37.80C and certain other substances specified in the Gas Codes.

  • A. none of the above
  • B. maintaining
  • C. decreasing
  • D. exceeding
Answer: D — exceeding
Under the IMO Gas Codes, a cargo is classified as a liquefied gas when its saturated vapor pressure exceeds 2.8 bar absolute at 37.8°C.

29. What is the major constituent of Liquefied Natural Gas?

  • A. Polybutadiene
  • B. Styrene
  • C. methane
  • D. Acrylonitrile
Answer: C — methane
Methane (CH4) is the predominant hydrocarbon constituent of Liquefied Natural Gas (LNG), typically comprising 85% to 99% of its composition.

30. What is lower flamable limit?

  • A. The concentration of a hydrocarbon gas in air below which there is insufficient hydrocarbon to support combustion.
  • B. The concentration of a carbon gas in air below which there is insufficient hydrocarbon to support combustion.
  • C. The concentration of a hydrogen gas in air below which there is insufficient hydrocarbon to support combustion.
  • D. The concentration of a nitrocarbon gas in air below which there is insufficient hydrocarbon to support combustion.
Answer: A — The concentration of a hydrocarbon gas in air below which there is insufficient hydrocarbon to support combustion.
The Lower Flammable Limit (LFL) is the minimum concentration of flammable vapor in air below which the mixture is too lean to ignite or sustain combustion.

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