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BIGF exit exam questions and answers

All 181 questions from the Basic Training for Ships subject to the IGF Code (BIGF) exit exam bank, with the correct option marked, and 169 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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Practise these BIGF questions BIGF mock exit exam, 30 marks BIGF exit exam sets and syllabus

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Set 1 — 30 BIGF exit exam questions with answers

1. IMO means ____________

  • A. International Main Oraganisation
  • B. Indian Marine Organisation
  • C. International Maritime Oraganisation
  • D. Indian Maritime Organisation
Answer: C — International Maritime Oraganisation
IMO stands for International Maritime Organization, the specialized agency of the United Nations responsible for regulating shipping safety, maritime security, and marine environmental protection.

2. A liquefied gas is the liquid form of a substance, which at _________________would be a gas.

  • A. both (a) and (b)
  • B. ambient temperature
  • C. none of the above
  • D. atmospheric pressure
Answer: A — both (a) and (b)
A liquefied gas is defined by the Gas Codes as the liquid form of a substance which, at ambient temperature and atmospheric pressure, would exist in a gaseous state.

3. The most important property of a liquified gas, in relation to pumping and storage is _____________

  • A. none of the above
  • B. low vapour pressure
  • C. high vapour pressure
  • D. saturated vapour pressure
Answer: D — saturated vapour pressure
Saturated Vapor Pressure (SVP) is the most critical physical property of a liquefied gas regarding pumping, storage, and tank pressure management.

4. Saturated vapour pressure is the ___________ pressure exerted when liquid is in equlibrium with its own vapour at a given temperature.

  • A. flexible
  • B. partial
  • C. relative
  • D. absolute
Answer: D — absolute
Saturated vapor pressure is the absolute pressure exerted by a vapor in thermodynamic equilibrium with its liquid phase at a given temperature in a closed system.

5. The most important property of a liquified gas, in relation to ___________ is saturated vapour pressure

  • A. storage
  • B. both (a) and (b)
  • C. pumping
  • D. none of the above
Answer: B — both (a) and (b)
Saturated vapor pressure directly governs both cargo pumping cavitation limits and fuel tank pressure containment requirements for liquefied gases.

6. Saturated vapour pressure is the absolute pressure exerted when _______ is in equlibrium with its own vapour at a given temperature.

  • A. vapour
  • B. liquid
  • C. solid
  • D. gas
Answer: B — liquid
Saturated vapor pressure is the absolute equilibrium pressure exerted by the evaporated vapor above the liquid surface at a specified temperature.

7. Saturated vapour pressure is the absolute pressure exerted when liquid is in ___________ with its own vapour at a given temperature.

  • A. none of the above
  • B. equlibrium
  • C. stability
  • D. tranquility
Answer: B — equlibrium
Thermodynamic equilibrium occurs when the rate of liquid evaporation equals the rate of vapor condensation at a constant temperature and pressure.

8. Liquid with a vapour pressure exceeding ________absolute at a temperature of 37.8 deg C.

  • A. 2.0 bar
  • B. 2.9 bar
  • C. 2.5 bar
  • D. 2.8 bar
Answer: D — 2.8 bar
Under the IMO IGC and IGF Codes, a liquefied gas is defined as a liquid having a saturated vapor pressure exceeding 2.8 bar absolute at a temperature of 37.8°C.

9. Liquid with a vapour pressure exceeding 2.8 bar absolute at a temperature of __________.

  • A. 38.8 deg C
  • B. 37.8 deg C
  • C. 36.8 deg C
  • D. 37.0 deg C
Answer: B — 37.8 deg C
The standard reference temperature defined in the IMO Gas Codes for classifying liquefied gases by vapor pressure (exceeding 2.8 bar absolute) is 37.8°C (100°F).

10. What are the cargoes carried on Liquified Gas Tankers?

  • A. Liquified Petroleum Gas
  • B. none of the above
  • C. Liquified Natural Gas
  • D. both (a) and (b)
Answer: D — both (a) and (b)

11. ____________ is transported either by pipeline as a gas or by sea in its liquified form as Liquified Natural Gas.

  • A. Natural gas
  • B. Ethane gas
  • C. Chemical gases
  • D. none of the above
Answer: A — Natural gas
Natural gas is transported either overland via pressurized pipeline grids or across oceans by specialized gas carriers in liquefied form as Liquefied Natural Gas (LNG).

12. Natural gas comes from ________________

  • A. heating mixtures
  • B. rocks
  • C. cold climate
  • D. underground deposits
Answer: D — underground deposits
Natural gas is a naturally occurring fossil fuel extracted from underground geological hydrocarbon reservoirs and gas fields.

13. In natural gas what is the range of methane ?

  • A. 50%
  • B. 70 to 99 %
  • C. 100%
  • D. 60 to 88%
Answer: B — 70 to 99 %
Methane (CH4) is the predominant component of raw and commercial natural gas, typically comprising 70% to 99% of the total gas volume.

14. Which is the major constituent of natural gas?

  • A. oxygen
  • B. ethane
  • C. methane
  • D. octane
Answer: C — methane
Methane is the lightest and primary constituent of natural gas, typically making up between 85% and 95%+ of Liquefied Natural Gas.

15. Methane is a petrochemical stock leading to the production of _________

  • A. acetic acid
  • B. acetaldehyde
  • C. methonal
  • D. ethanol
Answer: C — methonal
Methane is an essential petrochemical feedstock used in chemical synthesis plants for the commercial production of methanol and ammonia.

16. ____________ is a petrochemical stock leading to the production of methonal

  • A. Octane
  • B. Methane
  • C. Acetic acid
  • D. Ethane
Answer: B — Methane
Methane is reacted with steam (steam reforming) to produce synthesis gas, which is the primary feedstock for manufacturing methanol.

17. Methanol is a feedstock to ___________

  • A. both (a) and (b)
  • B. none of the above
  • C. Methyl tetra chloride
  • D. Formaldehyde
Answer: A — both (a) and (b)
Methanol is a versatile petrochemical intermediate widely used in the production of formaldehyde, acetic acid, solvents, and alternative marine fuels.

18. Associated gas found in combination with __________ comprises mainly methane and Natural Gas Liquids

  • A. gas
  • B. crude oil
  • C. diesel
  • D. petroluem
Answer: B — crude oil
Associated gas is natural gas found in reservoir contact with crude oil, containing methane along with heavier Natural Gas Liquids (NGLs).

19. Associated gas found in combination with crude oil comprises mainly ______________

  • A. none of the above
  • B. methane
  • C. both (a) and (b)
  • D. Natural Gas Liquids
Answer: C — both (a) and (b)
Associated petroleum gas consists of a mixture of methane and heavier fractions known as Natural Gas Liquids (ethane, propane, butane, pentane).

20. Natural Gas Liquids are made up of __________

  • A. Liquified Petroleum Gas
  • B. none of the above
  • C. ethane
  • D. both (a) and (b)
Answer: D — both (a) and (b)
Natural Gas Liquids (NGL) comprise the heavier hydrocarbon fractions of natural gas, primarily ethane, propane, butane, isobutane, and natural gasoline.

21. Natural Gas Liquids are carried at- _________ at atmospheric pressure

  • A. 37oC
  • B. 35oC
  • C. 36oC
  • D. 80oC
Answer: D — 80oC
Heavier Natural Gas Liquid fractions can be refrigerated and carried as liquids at temperatures down to -80°C at atmospheric pressure.

22. Natural Gas Liquids are carried at- _________ at atmospheric vapour pressure of 5 bar

  • A. 135degc
  • B. 400degC
  • C. 45degc
  • D. 550degc
Answer: C — 45degc
Semi-pressurized carriage allows certain liquefied gas fractions to be transported at temperatures around -45°C under a vapor pressure of approximately 5 bar.

23. Natural Gas Liquids are carried at -45deg C at vapour pressure of __________

  • A. 15 bar
  • B. 7 bar
  • C. 5 bar
  • D. 25 bar
Answer: C — 5 bar
Carriage of liquefied petroleum gases in semi-refrigerated tanks is commonly maintained at -45°C with a designed working vapor pressure of about 5 bar.

24. Liquified Petroleum Gas is a comprise of ________________

  • A. propane
  • B. none of the above
  • C. butane
  • D. both (a) and (b)
Answer: D — both (a) and (b)
Liquefied Petroleum Gas (LPG) consists primarily of propane (C3H8), butane (C4H10), or commercial mixtures of both hydrocarbons.

25. What is the use of bottled gas?

  • A. none of the above
  • B. both (a) and (b)
  • C. cooking in remote loctions
  • D. fuel for heating
Answer: B — both (a) and (b)
Commercial bottled gas (LPG cylinders) is widely utilized for domestic heating, commercial cooking, automotive fuel (autogas), and industrial cutting.

26. Which is an important octane enhancer for motor gasoline?

  • A. kerosene
  • B. crude oil
  • C. water
  • D. butane
Answer: D — butane
Commercial butane and isobutane are critical blending agents and octane enhancers utilized in the refining of motor gasoline.

27. Which is used as bottled gas in cold climates?

  • A. ammonia
  • B. both (a) and (b)
  • C. propane
  • D. none of the above
Answer: C — propane
Propane has a lower boiling point (-42°C) than butane (-0.5°C), allowing it to vaporize easily and serve as bottled gas in cold climates.

28. Liquified Petroleum Gas is mainly used in ________

  • A. power generation
  • B. All of the above
  • C. petrochemical feedstock
  • D. metal cutting
Answer: B — All of the above
LPG is utilized globally as domestic cooking fuel, industrial heating fuel, automotive autogas, and as petrochemical cracker feed.

29. Used as Petrochemical feedstock for the production of ________

  • A. both (a) and (b)
  • B. none of the above
  • C. acetic acid
  • D. acetaldehyde
Answer: A — both (a) and (b)
LPG fractions (propane and butane) are vital petrochemical feedstocks for steam cracking into olefins like ethylene and propylene.

30. ____________ accounts the large for the third largest sea borne trade in liquified gases after Liquified Natural Gas and Liquified Petroleum Gas

  • A. Urea
  • B. Ammonia
  • C. both (a) and (b)
  • D. none of the above
Answer: B — Ammonia
Anhydrous ammonia (NH3) represents the third largest seaborne trade volume among liquefied gases, following LNG and LPG, primarily used for agricultural fertilizers.

Set 2 — 30 BIGF exit exam questions with answers

1. _________ is the primary petrochemical building blocks

  • A. kerosene
  • B. none of the above
  • C. Ethylene
  • D. chlorine
Answer: C — Ethylene
Ethylene (C2H4) is the world's primary organic chemical building block, serving as the base precursor for polyethylene plastics, ethylene glycol, and vinyls.

2. Ethane is obtained by cracking____________

  • A. ethane
  • B. naphtha
  • C. none of the above
  • D. both (a) and (b)
Answer: D — both (a) and (b)
Ethane is extracted from natural gas streams or refinery off-gases and thermal cracked in petrochemical plants to produce ethylene.

3. Products obatined from ethylene are

  • A. polyethylene
  • B. polyvinyl chloride
  • C. All of the above
  • D. rubber
Answer: C — All of the above
Ethylene is the primary precursor for polyethylene (HDPE, LDPE), ethylene dichloride (EDC for PVC), ethylene oxide, and synthetic alcohols.

4. Propylene is a petrochemical intermediate used to make which product

  • A. All of the above
  • B. Acetone
  • C. Phenol
  • D. Detergent
Answer: A — All of the above
Propylene is a key chemical intermediate used to synthesize polypropylene plastics, acrylonitrile (acrylic fibers), propylene oxide, and cumene.

5. Butadiene is a _______________ petrochemical intermediaste.

  • A. medium reactive
  • B. none of the above
  • C. high reactive
  • D. low reactive
Answer: C — high reactive
1,3-Butadiene is a highly reactive, flammable conjugated diene petrochemical intermediate that requires polymerization inhibitors during marine transport.

6. Butadiene is used in

  • A. binders
  • B. intermediate in plastics
  • C. paints
  • D. All of the above
Answer: D — All of the above
Butadiene is primarily utilized in the production of synthetic elastomers, styrene-butadiene rubber (SBR) for vehicle tires, and ABS engineering plastics.

7. What are the products from Butadiene?

  • A. Synthetic rubbers
  • B. Polybutadiene
  • C. All of the above
  • D. Styrene
Answer: C — All of the above
Key industrial end-products derived from butadiene include polybutadiene rubber, nitrile rubber (NBR), neoprene, and nylon intermediates.

8. Vinyl Chloride is an easily ___________ used in the manufacture of polyvinyl chloride

  • A. chlorinated gas
  • B. none of the above
  • C. liquefiable
  • D. both (a) and (b)
Answer: D — both (a) and (b)
Vinyl Chloride Monomer (VCM) is a chlorinated gas that is readily liquefied under mild pressure or refrigeration, used to manufacture polyvinyl chloride (PVC).

9. _______________ is an easily liquefiable and chlorinated gas used in the manufacture of polyvinyl chloride

  • A. oxygen
  • B. none of the above
  • C. florine
  • D. Vinyl Chloride
Answer: D — Vinyl Chloride
Vinyl Chloride Monomer (VCM) is an organochloride gas essential to the global plastics industry for manufacturing PVC pipes and construction materials.

10. Vinyl Chloride has a ____________ boiling point at - 14 deg C.

  • A. high
  • B. low
  • C. zero
  • D. medium
Answer: A — high
Vinyl Chloride Monomer has an atmospheric boiling point of -13.8°C (approx. -14°C), allowing it to be transported in semi-pressurized or fully refrigerated gas carriers.

11. Vinyl Chloride has a ____________specific gravity much denser than other common gas.

  • A. 0.67
  • B. 0.87
  • C. 0.57
  • D. 0.97
Answer: D — 0.97
Vinyl Chloride Monomer vapor has a high liquid specific gravity (approx. 0.97 at boiling point) and a heavy vapor density (2.15 times heavier than air).

12. Gas shipping began in which year?

  • A. 1920
  • B. 2000
  • C. 1520
  • D. 2019
Answer: A — 1920

13. In which year fully refrigerated ships for Liquified Petroleum Gas, Liquified Natural Gas and certain chemical gases.

  • A. 2010
  • B. 2019
  • C. 1963
  • D. 1900
Answer: C — 1963
The era of modern fully refrigerated ocean-going LNG and LPG carriers began in the early 1960s with purpose-built insulated containment systems.

14. Absolute pressure is the total of ___________

  • A. pressure of surrounding atmosphere
  • B. gauge pressure
  • C. both (a) and (b)
  • D. none of the above
Answer: C — both (a) and (b)
Absolute pressure is defined as the total pressure exerted on a surface, equal to gauge pressure plus local atmospheric pressure (P_abs = P_gauge + P_atm).

15. In practical calculations for Celcius to Kelvin _____________ is added

  • A. 373
  • B. 473
  • C. 73
  • D. 273
Answer: D — 273
To convert temperatures from the Celsius scale to the absolute thermodynamic Kelvin scale, 273.15 (commonly rounded to 273) is added to the Celsius value.

16. Absolute zero is the temperature at which the volume of gas theoretically becomes _____________

  • A. high
  • B. low
  • C. medium
  • D. zero
Answer: D — zero
Absolute zero (0 Kelvin or -273.15°C) is the theoretical thermodynamic state where molecular kinetic energy reaches its minimum and gas volume theoretically extrapolates to zero.

17. Absolute zero is _____________

  • A. being -473.16 deg C
  • B. being -273.16 deg C
  • C. none of the above
  • D. being -373.16 deg C
Answer: B — being -273.16 deg C
Absolute zero corresponds to exactly -273.15°C (or -273.16°C in early thermometry definitions relative to the triple point of water).

18. Activated Alumina a desiccant medium which operates by adsorption of ___________

  • A. gauge pressure
  • B. water molecules
  • C. pressure of surrounding atmosphere
  • D. gas
Answer: B — water molecules
Activated alumina is a highly porous desiccant adsorbent used in gas carrier dehumidifiers to remove moisture by physical adsorption of water molecules.

19. Adiabatic is an ideal process undergone by a gas in which__________ occurs

  • A. no loss of heat
  • B. no gain of heat
  • C. both (a) and (b)
  • D. none of the above
Answer: C — both (a) and (b)
An adiabatic process is an idealized thermodynamic process in which no heat energy is transferred into or out of the working fluid system (Q = 0).

20. Aerating means the introduction of fresh air into a tank with the object of removing

  • A. toxic
  • B. inert gas
  • C. All of the above
  • D. flamamable
Answer: C — All of the above
Aerating or gas-freeing is the controlled introduction of fresh air into a purged cargo or fuel tank to displace inert gas and restore a safe, breathable atmosphere.

21. Aerating means _____________ the oxygen content by 21 percent by volume.

  • A. decreasing
  • B. increasing
  • C. maintaining
  • D. none of the above
Answer: B — increasing
Aerating tank spaces increases the oxygen content back to normal atmospheric levels (20.9% to 21.0% oxygen by volume) before personnel entry.

22. Air lock is used to maintain _____________ areas at a pressure differential.

  • A. adjacent
  • B. non adjacent
  • C. none of the above
  • D. opposite
Answer: A — adjacent
Air locks maintain a positive overpressure barrier between non-hazardous gas-safe spaces (such as accommodation or control rooms) and adjacent hazardous deck zones.

23. __________ is the lowest temperature to which a liquid or gas requires to be raised to cause self- sustained spontaneous combustion

  • A. Boiling Point
  • B. Absolute Zero
  • C. Auto-Ignition Temperature
  • D. Absolute Temperature
Answer: C — Auto-Ignition Temperature
Auto-ignition temperature (AIT) is the lowest temperature at which a flammable vapor-air mixture will spontaneously ignite without an external spark or flame.

24. BLEVE means

  • A. Boiling Liquid Expanding Vapour Explosion
  • B. Boiling Liquid Exploring Vapour Explosion
  • C. Boil-off Liquid Expanding Vapour Explosion
  • D. Boil-off Liquid Exploring Vapour Explosion
Answer: A — Boiling Liquid Expanding Vapour Explosion
BLEVE stands for Boiling Liquid Expanding Vapor Explosion, a catastrophic structural failure of a pressure vessel containing a superheated liquefied gas.

25. BLEVE is associated with _________of pressure vessel containing liquified gas

  • A. rupture
  • B. under fire conditions
  • C. none of the above
  • D. both (a) and (b)
Answer: C — none of the above
A BLEVE occurs when external heat weakens a pressurized vessel containing liquefied gas, causing catastrophic tank rupture and rapid explosive vaporization.

26. ___________ is the vapour produced above the surface of a boiling cargo due to evaporation.

  • A. BLEVE
  • B. Boiling Point
  • C. Absolute Temperature
  • D. Boil-off
Answer: D — Boil-off
Boil-off gas (BOG) is the continuous vapor generated above the liquid surface inside cryogenic fuel tanks due to unavoidable ambient heat ingress.

27. Boil-Off is caused by

  • A. none of the above
  • B. both (a) and (b)
  • C. heat ingress
  • D. drop in pressure
Answer: B — both (a) and (b)
Boil-off gas formation is primarily caused by heat ingress through tank insulation and changes in atmospheric or tank vapor pressure.

28. Boiling point varies with

  • A. drop in pressure
  • B. discharge pressure
  • C. exerted pressure
  • D. none of the above
Answer: C — exerted pressure
The boiling point of any pure liquid is directly dependent upon the external pressure exerted upon its liquid surface.

29. Boil-Off varies with

  • A. discharge pressure
  • B. high pressure
  • C. exerted pressure
  • D. drop in pressure
Answer: D — drop in pressure
The rate of boil-off vapor generation increases whenever there is a drop in tank pressure or an increase in thermal heat transmission into the cargo.

30. Booster pump used to

  • A. exerted pressure
  • B. increase the discharge pressure from another pump
  • C. high pressure
  • D. drop in pressure
Answer: B — increase the discharge pressure from another pump
Methane boils at -161.5°C at atmospheric pressure and has a molecular weight of 16.04 g/mol, making cold methane vapor lighter than air once warmed above approx. -110°C.

Set 3 — 30 BIGF exit exam questions with answers

1. Cargo area contains

  • A. cargo containment system
  • B. cargo pumps
  • C. All of the above
  • D. compressor rooms
Answer: C — All of the above

2. Cargo containment system is the arrangement for containment of cargo including where fitted with

  • A. primary barriers
  • B. associated insulations
  • C. secondary barriers
  • D. All of the above
Answer: D — All of the above
Propane boils at -42.1°C at atmospheric pressure; its vapor is approximately 1.5 times heavier than air, causing leaks to settle in low areas.

3. ______________ is the process in which vapour boil- off from acrgo tanks is condensed in a cargo condenser in which the coolant is a refrigerant gas such as R 22.

  • A. Boil-off
  • B. Cascade Reliquefaction Cycle
  • C. BLEVE
  • D. Boiling Point
Answer: B — Cascade Reliquefaction Cycle

4. _____________ is the process occurring within the impeller of a pump when pressure at the inlet to the impeller falls below the vapour pressure of the liquid being pumped.

  • A. Cascade Reliquefaction Cycle
  • B. Boil-off
  • C. Cavitation
  • D. BLEVE
Answer: C — Cavitation
Ethylene boils at -103.7°C at atmospheric pressure and is transported in specialized semi-pressurized or fully refrigerated ethylene carriers.

5. In Cavitation process, the bubbles of vapour that are formed collapse with impulsive force in the _________ pressure regions of the impeller.

  • A. medium
  • B. lower
  • C. higher
  • D. zero
Answer: C — higher
Propylene (propene) has a boiling point of -47.6°C at atmospheric pressure and is carried under refrigeration or pressure in LPG carriers.

6. Cavitation effect can cause significant damage to the

  • A. pumps may lose suction
  • B. impeller surfaces
  • C. both (a) and (b)
  • D. none of the above
Answer: C — both (a) and (b)
Anhydrous ammonia boils at -33.3°C; it is toxic, corrosive to copper and copper alloys, and has an alkaline, pungent odor.

7. What are checked during the certificate of Fittness?

  • A. structure
  • B. All of the above
  • C. equipment
  • D. fittings
Answer: B — All of the above

8. ___________ ia the isolating space on a ship between two adjacent steel bulkheads or deck

  • A. Cofferdam
  • B. Cargo conatinment system
  • C. Compressor pumps
  • D. Cavitation
Answer: A — Cofferdam
Chemical gas carriers carry unsaturated hydrocarbons and monomers that can react or polymerize unless treated with suitable chemical inhibitors.

9. Cofferdam is the isolating space on a ship between __________

  • A. both (a) and (b)
  • B. none of the above
  • C. deck
  • D. two adjacent steel bulkheads
Answer: A — both (a) and (b)

10. ___________ is the reliquefied gases which collect in the condenser and which are then returned to the cargo tanks.

  • A. BLEVE
  • B. Cofferdam
  • C. Condensate
  • D. Aerating
Answer: C — Condensate

11. Compression Ratio is the ratio of the absolute _____________ the discharge from a compressor divided by the absolute pressure at the suction

  • A. mass
  • B. temperature
  • C. pressure
  • D. volume
Answer: C — pressure

12. _____________ is the ratio of the absolute pressure at the discharge from a compressor divided by the absolute pressure at the suction

  • A. Temperature Ratio
  • B. Compression Ratio
  • C. Compressing ratio
  • D. Freezing ratio
Answer: B — Compression Ratio

13. Natural gas contains ________ quantities of heavier hydrocarbons

  • A. zero
  • B. medium
  • C. bigger
  • D. smaller
Answer: D — smaller

14. Natural gas contains smaller quantities of ______hydrocarbons

  • A. medium
  • B. heavier
  • C. lighter
  • D. partial
Answer: B — heavier

15. Natural gas contains smaller quantities of heavier ________

  • A. hydrocarbons
  • B. carbons
  • C. nitrogen
  • D. oxygen
Answer: A — hydrocarbons
Cryogenic liquid fuel leaks cause severe cold contact burns, frostbite, and extreme embrittlement of standard mild structural steel.

16. Natural gas contains smaller quantities of heavier hydrocarbons collectively called as _________

  • A. Neutral Gas Liquid
  • B. Natural Gas Limit
  • C. Natural Gas Liquid
  • D. Nitrogen Gas Liquid
Answer: C — Natural Gas Liquid
Natural Gas Liquids (NGL) refer to the heavier hydrocarbon components (ethane, propane, butane, pentane plus) separated from raw natural gas streams.

17. What are the things Natural gas contains in varying amounts?

  • A. carbondioxide
  • B. hydrocarbon
  • C. All of the above
  • D. water
Answer: C — All of the above
Raw natural gas contains methane, ethane, propane, butane, inert gases (nitrogen, helium), and acid contaminants (CO2, H2S, mercaptans).

18. What are the acid gases removed in liquefaction plant?

  • A. carbon dioxide
  • B. none of the above
  • C. both (a) and (b)
  • D. hydrogen sulphide
Answer: C — both (a) and (b)
Acid gases like carbon dioxide (CO2) and hydrogen sulfide (H2S) must be scrubbed from natural gas before liquefaction to prevent corrosion and freezing.

19. In liquefaction plant which gas is removed as it freezes at a temperature above boiling point of Liquified Natural Gas

  • A. methane
  • B. ethane
  • C. carbon dioxide
  • D. hydrocarbons
Answer: C — carbon dioxide
Carbon dioxide freezes at -78.5°C, well above the liquefaction temperature of LNG (-162°C), and must be removed to prevent solid plugging in heat exchangers.

20. In liquefaction plant which toxic compound is removed?

  • A. All of the above
  • B. nitrogen sulphide
  • C. hydrogen sulphide
  • D. carbondioxide
Answer: C — hydrogen sulphide
Hydrogen sulfide (H2S) is a highly toxic, corrosive gas removed during gas sweetening processes to meet safety and transport specifications.

21. In liquefaction plant, fractionating unit name the gas which is split?

  • A. Butane
  • B. none of the above
  • C. Propane
  • D. both (a) and (b)
Answer: D — both (a) and (b)

22. In liquefaction plant, which gas is liquefied into end product?

  • A. Oxygen
  • B. none of the above
  • C. hydrogen
  • D. Methane
Answer: D — Methane
In an LNG liquefaction plant, the purified, chilled methane stream is liquefied and sent to cryogenic storage tanks as the final LNG product.

23. What is the atmospheric boiling point of methane gas?

  • A. atmospheric boiling point is +172deg C
  • B. atmospheric boiling point is - 162deg C
  • C. atmospheric boiling point is +192deg C
  • D. atmospheric boiling point is +162deg C
Answer: B — atmospheric boiling point is - 162deg C
The boiling point of methane at normal atmospheric pressure (1.013 bar) is approximately -161.5°C (standard rounded to -162°C).

24. The basic liquefaction processes in current use are

  • A. Pre-cooled mixed refrigerant process
  • B. Pure refrigerant cascade process
  • C. All of the above
  • D. Mixed refrigerant process
Answer: C — All of the above
Major commercial LNG liquefaction cycles include the C3MR (propane pre-cooled mixed refrigerant) process, cascade cycles, and nitrogen expansion loops.

25. In Pre-cooled mixed refrigerant process, what is MCR

  • A. Multi Component Refrigerant
  • B. Multi Cascade Refinement
  • C. Minimum Combination Refrigerant
  • D. Multi Cascade Refrigerant
Answer: A — Multi Component Refrigerant
MCR stands for Multi-Component Refrigerant (or Mixed Refrigerant), utilizing a optimized blend of nitrogen, methane, ethane, and propane.

26. In Pre-cooled mixed refrigerant process, Multi Component Refrigerant is a combination of

  • A. both (a) and (b)
  • B. none of the above
  • C. mixed refrigerant cycles
  • D. pure refrigerant cascadecycles
Answer: A — both (a) and (b)
The mixed refrigerant stream in LNG liquefaction plants consists of tailored mixtures of nitrogen, methane, ethane/ethylene, propane, and butane.

27. Liquefied Petroleum Gas is obtained from the refining of __________

  • A. All of the above
  • B. crude oil
  • C. Vegetable oil
  • D. fatty oil
Answer: B — crude oil
Commercial LPG is produced both by extracting NGLs from natural gas processing and through fractional distillation and catalytic cracking of crude oil.

28. In production of chemical gases, from Propane which gas is produced indirectly

  • A. ammonia
  • B. All of the above
  • C. vinyl chloride
  • D. ethylene
Answer: B — All of the above
Propane dehydrogenation and petrochemical cracking processes produce chemical intermediates such as propylene, ethylene, and downstream derivatives.

29. In production of chemical gases, The ethylene stream can be synthesized with chlorine to manufacture __________

  • A. vinyl chloride
  • B. ethylene
  • C. All of the above
  • D. ammonia
Answer: A — vinyl chloride
Ethylene is chlorinated to form ethylene dichloride (EDC), which is then thermally cracked to produce Vinyl Chloride Monomer (VCM) for PVC production.

30. In production of chemical gases, The methane stream is first reformed with steam into _________

  • A. nitrogen
  • B. hydrogen
  • C. vinyl chloride
  • D. carbondioxide
Answer: B — hydrogen
In chemical synthesis, methane is reacted with high-temperature steam over a nickel catalyst in steam methane reforming (SMR) to produce hydrogen and carbon monoxide.

Set 4 — 30 BIGF exit exam questions with answers

1. In production of chemical gases, By combining with nitrogen under high pressure and temperature in the presence of a catalyst __________ is produced.

  • A. hydrogen
  • B. carbondioxide
  • C. ammonia
  • D. vinyl chloride
Answer: C — ammonia
Ammonia is synthesized industrially via the Haber-Bosch process by reacting reformed hydrogen with atmospheric nitrogen under high pressure and temperature over an iron catalyst.

2. In IGF Code, L is the _______ as defined in the International Convention on Load Lines in force.

  • A. less
  • B. length
  • C. least
  • D. lower
Answer: B — length
Under the IGF Code, vessel Length (L) is defined in accordance with the International Convention on Load Lines in force.

3. In IGF Code, Length (L) is the length as defined in the ___________ in force

  • A. International Convention on Level Lines
  • B. Indian Convention on Load Lines
  • C. International Convention on Load Lines
  • D. Independent Convention on Load Lines
Answer: C — International Convention on Load Lines
The standard definition of ship length (L) in the IGF Code references the criteria specified under the International Convention on Load Lines.

4. In IGF Code, MARVS means

  • A. Minimum allowable relief value setting
  • B. Maximum allowable relief value setting
  • C. Minimum allowable relief valve setting
  • D. Maximum allowable relief valve setting
Answer: D — Maximum allowable relief valve setting
MARVS stands for Maximum Allowable Relief Valve Setting, the design pressure limit set on cargo/fuel tank pressure relief valves.

5. In IGF Code, MAWP means

  • A. Minimum allocated working pressure
  • B. Maximum allowable working pressure
  • C. Minimum allowable working pressure
  • D. Maximum allocated working pressure
Answer: B — Maximum allowable working pressure
MAWP stands for Maximum Allowable Working Pressure, the maximum gauge pressure permissible at the top of a tank or piping system in operational service.

6. In IGF Code, Membrane tanks means

  • A. an tank in which an explosive gas atmosphere a flammable gas or vapour is or may be expected to be present
  • B. an tank in which an explosive gas atmosphere or a flammable gas or vapour is present continuously or is present for long periods
  • C. self-supporting, do not form part of the ship's hull and are not essential to the hull strength
  • D. non-self-supporting tanks that consist of a thin liquid and gas tight layer membrane) supported through insulation by the djacent hull structure
Answer: D — non-self-supporting tanks that consist of a thin liquid and gas tight layer membrane) supported through insulation by the djacent hull structure
Membrane tanks are non-self-supporting fuel containment systems composed of a thin liquid and gas-tight metallic barrier supported through load-bearing insulation by the adjacent inner hull.

7. What is critical pressure?

  • A. The pressure at which a substance exists in the solid state at its critical temperature.
  • B. The pressure at which a substance exists in the liquid state at its critical temperature.
  • C. ATMOSPHERIC PRESSURE
  • D. none of the above
Answer: B — The pressure at which a substance exists in the liquid state at its critical temperature.
Critical pressure is the minimum pressure required to liquefy a gas at its critical temperature.

8. The pressure at which a substance exists in the _______ state at its critical temperature is called critical pressure.

  • A. semi solid
  • B. liquid
  • C. solid
  • D. vapour
Answer: B — liquid
Critical pressure represents the saturation pressure corresponding to the substance's critical point temperature where liquid and vapor phases become indistinguishable.

9. Explanation for critical pressure?

  • A. The pressure at which a substance exists in the liquid state at its critical temperature is called critical pressure.
  • B. both (a) and (b)
  • C. Critical pressure is the saturation pressure at the critical temperature.
  • D. none of the above
Answer: B — both (a) and (b)
At the critical point, the liquid and vapor densities become equal and no distinct phase boundary exists, regardless of additional pressure application.

10. Critical temperature is ________________

  • A. The temperature above which a semi solid cannot be liquefied by pressure alone.
  • B. The temperature above which a gas cannot be liquefied by pressure alone.
  • C. none of the above
  • D. The temperature above which a solid cannot be liquefied by pressure alone.
Answer: B — The temperature above which a gas cannot be liquefied by pressure alone.
Critical temperature is the maximum temperature above which a gas cannot be liquefied, no matter how much external pressure is applied.

11. ________________ is the temperature above which a gas cannot be liquefied by pressure alone.

  • A. Absolute temperature
  • B. Critical temperature
  • C. Critical pressure
  • D. Absolute pressure
Answer: B — Critical temperature
Above the critical temperature, a substance exists solely as a supercritical fluid and cannot be condensed into a distinct liquid phase by pressure alone.

12. ______________ is the endorsement issued by a flag state administration to a certificate of competency of a ship's officer allowing service on dangerous cargo carriers such as oil tankers, chemical tankers or gas carriers.

  • A. Bulk cargo
  • B. EXEMPTION
  • C. Dangerous Cargo Endorsement
  • D. Cargo containment system
Answer: C — Dangerous Cargo Endorsement
A Dangerous Cargo Endorsement (DCE) is a statutory endorsement issued by the maritime administration to an officer's Certificate of Competency for service on tankers or gas carriers.

13. Dangerous Cargo Endorsement is the endorsement issued by a flag state administration to a certificate of competency of a ship's office rallowing service on dangerous cargo carriers such as ______________

  • A. chemical tankers
  • B. gas carriers
  • C. All of the above
  • D. oil tankers
Answer: C — All of the above
Dangerous Cargo Endorsements are required under STCW regulations for certified officers serving on oil tankers, chemical tankers, and liquefied gas carriers.

14. Dangerous Cargo Endorsement is the endorsement issued by a flag state administration to a ______________ ship's officer allowing service on dangerous cargo carriers such as oil tankers, chemical tankers or gas carriers.

  • A. continuous discharge certificate
  • B. Indos
  • C. certificate of competency
  • D. none of the above
Answer: C — certificate of competency
A Dangerous Cargo Endorsement is formally attached to the officer's Certificate of Competency (CoC) upon satisfying mandatory STCW sea time and specialized training.

15. Density is the mass per unit volume of a substance at specified conditions of_________

  • A. temperature
  • B. none of the above
  • C. both (a) and (b)
  • D. pressure
Answer: C — both (a) and (b)
Density is the physical mass of a substance per unit volume (kg/m³), which varies as a function of temperature and pressure.

16. ________ is the mass per unit volume of a substance at specified conditions of temperaure and pressure.

  • A. Volume
  • B. Dew point
  • C. Density
  • D. Pressure point
Answer: C — Density
Density expresses the ratio of mass to volume of a fuel gas or liquid at standard reference temperature and pressure conditions.

17. ___________ is the temperature at which condensation will take place within a gas if further cooling occurs.

  • A. Flame
  • B. Enthalpy
  • C. Bleve
  • D. Dew point
Answer: D — Dew point
Dew point is the saturation temperature at which water vapor or hydrocarbon gas begins to condense into liquid droplets upon cooling at constant pressure.

18. Enthalpy is a ___________ measure of the total heat content of a lliquid at a given temperature.

  • A. equlibria
  • B. irreversible
  • C. reversible
  • D. thermodynamic
Answer: D — thermodynamic
Enthalpy is a fundamental thermodynamic state property representing the total heat energy content (internal energy plus pressure-volume work) of a substance.

19. Enthalpy is expressed in ____________

  • A. k joules per unit
  • B. k joules per 1 kg
  • C. k joules per M
  • D. k joules per volume
Answer: B — k joules per 1 kg
Specific enthalpy in maritime thermodynamics is standardly expressed in units of kilojoules per kilogram (kJ/kg).

20. In Enthalpy, for a liquid / vapour mixture, it will be seen that it is the sum of ________________

  • A. the latent heat of vaporization
  • B. the enthalpy of the liquid
  • C. none of the above
  • D. both (a) and (b)
Answer: D — both (a) and (b)
For a saturated liquid-vapor mixture, total enthalpy is the sum of liquid sensible enthalpy and the latent heat of vaporization multiplied by vapor quality.

21. Synonyms of methane is

  • A. marsh gas
  • B. LNG
  • C. natural gas
  • D. All of the above
Answer: D — All of the above
Methane (CH4) is also commonly known as marsh gas, firedamp, methyl hydride, or natural gas.

22. Synonyms of ethane is

  • A. methyl methane
  • B. dimethyl
  • C. bimethyl
  • D. All of the above
Answer: D — All of the above
Ethane (C2H6) is also referred to as bimethyl, dimethyl, or ethyl hydride.

23. Synonyms of n-butane is

  • A. iso butane
  • B. methlypropane
  • C. All of the above
  • D. normal butane
Answer: D — normal butane
n-Butane refers to normal butane (unbranched straight-chain C4H10 hydrocarbon).

24. Synonyms of i-butane is

  • A. methlypropane
  • B. none of the above
  • C. iso butane
  • D. both (a) and (b)
Answer: D — both (a) and (b)
Isobutane (i-butane) is 2-methylpropane, a branched constitutional isomer of butane.

25. Synonyms of ethylene is

  • A. bimethyl
  • B. dimethyl
  • C. propane
  • D. ethane
Answer: D — ethane
Ethylene is the IUPAC-recognized name ethene, an unsaturated hydrocarbon with a carbon-carbon double bond (C2H4).

26. Synonyms of propylene is

  • A. dimethyl
  • B. ethane
  • C. propane
  • D. bimethyl
Answer: C — propane
Propylene is systematically named propene, an unsaturated hydrocarbon with the chemical formula C3H6.

27. Synonyms of α butylene is

  • A. none of the above
  • B. But-1-ene
  • C. both (a) and (b)
  • D. ethyl ethylene
Answer: C — both (a) and (b)
Alpha-butylene refers to 1-butene (C4H8), an unsaturated terminal alkene monomer.

28. Under STCW Code Table A-V/3-1, what is the mandatory requirement regarding environmental protection and MARPOL standards during Basic IGF Code operations?

  • A. Optional adherence based on vessel size
  • B. Strict compliance with approved safety procedures and flag state regulations
  • C. Verbal recommendation without documentation
  • D. Applicable only during drydock operations
Answer: B — Strict compliance with approved safety procedures and flag state regulations
STCW Code Table A-V/3-1 mandates strict compliance with approved safety protocols for Basic IGF Code.

29. What specific safety precaution must be observed when managing environmental protection and MARPOL standards for Basic IGF Code on board?

  • A. Disabling automated safety alarms to save time
  • B. Conducting a thorough risk assessment and briefing all involved personnel prior to starting work
  • C. Proceeding without informing the officer on watch
  • D. Delegating tasks exclusively to untrained crew members
Answer: B — Conducting a thorough risk assessment and briefing all involved personnel prior to starting work
Risk assessments and pre-job briefings ensure all team members understand hazards during Basic IGF Code operations.

30. Which international regulation specifies the minimum standard for environmental protection and MARPOL standards concerning Basic IGF Code?

  • A. Port State Control advisory note only
  • B. International Load Line Certificate Annex 3
  • C. Tonnage Measurement Convention 1969
  • D. STCW Code Section A-V/3-1 and relevant SOLAS/MARPOL conventions
Answer: D — STCW Code Section A-V/3-1 and relevant SOLAS/MARPOL conventions
STCW Code Section A-V/3-1 sets international standards for training and operational competency in Basic IGF Code.

Set 5 — 30 BIGF exit exam questions with answers

1. In the event of an emergency involving environmental protection and MARPOL standards during Basic IGF Code tasks, what immediate action is required?

  • A. Attempt to resolve the incident silently without raising the alarm
  • B. Evacuate the vessel immediately without informing the bridge
  • C. Raise the alarm, notify the Officer of the Watch, and execute assigned muster list duties
  • D. Wait until the end of the watch to log the issue
Answer: C — Raise the alarm, notify the Officer of the Watch, and execute assigned muster list duties
Prompt alarm activation ensures emergency response teams can mobilize immediately.

2. How frequently must operational drills and practical checks for environmental protection and MARPOL standards be conducted for Basic IGF Code?

  • A. Only when requested by port State control inspectors
  • B. At least monthly or as mandated by SOLAS and shipboard safety management system (SMS)
  • C. Annually prior to vessel drydocking
  • D. Once every 5 years during special survey
Answer: B — At least monthly or as mandated by SOLAS and shipboard safety management system (SMS)
Regular drills maintain crew emergency readiness and satisfy SOLAS requirements.

3. What documented record must be maintained on board following completion of tasks related to environmental protection and MARPOL standards in Basic IGF Code?

  • A. Unsigned note on the shipboard notice board
  • B. Verbal update to port agent without logging
  • C. Entry in the official Deck or Engine Logbook recording date, time, and operational parameters
  • D. No written record is required
Answer: C — Entry in the official Deck or Engine Logbook recording date, time, and operational parameters
Official logbook entries provide mandatory legal documentation of shipboard safety tasks.

4. What type of personal protective equipment (PPE) is essential when handling environmental protection and MARPOL standards under Basic IGF Code guidelines?

  • A. Certified task-specific PPE meeting SOLAS/IMO performance standards
  • B. High-visibility vest only
  • C. Standard street clothing with rubber gloves
  • D. Basic cotton coveralls without eye or foot protection
Answer: A — Certified task-specific PPE meeting SOLAS/IMO performance standards
Approved PPE protects personnel against specific physical and chemical hazards.

5. What parameter must be verified prior to authorizing enclosed space entry for environmental protection and MARPOL standards related to Basic IGF Code?

  • A. Temperature check only
  • B. Oxygen level at 15% with ventilation turned off
  • C. Visual inspection through access hatch without gas testing
  • D. Atmospheric oxygen level at 20.9% and zero toxic/flammable gas concentration
Answer: D — Atmospheric oxygen level at 20.9% and zero toxic/flammable gas concentration
Enclosed space safety requires verified atmospheric gas testing prior to entry.

6. What key responsibility belongs to seafarers performing watchkeeping duties for environmental protection and MARPOL standards under Basic IGF Code?

  • A. Continuous monitoring of operational parameters and immediate reporting of anomalies
  • B. Bypassing safety trips during routine operations
  • C. Operating equipment beyond design pressure limits
  • D. Leaving watchkeeping station unattended
Answer: A — Continuous monitoring of operational parameters and immediate reporting of anomalies
Continuous vigilance and prompt communication are core watchkeeping duties under STCW.

7. Which document contains detailed hazard data and emergency handling instructions for substances involved in environmental protection and MARPOL standards during Basic IGF Code?

  • A. Bill of Lading description
  • B. Crew List document
  • C. Ship's Cargo Manifest summary page
  • D. Safety Data Sheet (SDS) / Material Safety Data Sheet (MSDS)
Answer: D — Safety Data Sheet (SDS) / Material Safety Data Sheet (MSDS)
Safety Data Sheets provide critical hazard identification, PPE requirements, and first aid response steps.

8. What are the arrangements complyied with the following requirements?

  • A. Failure developments that can be reliably detected before reaching a critical state
  • B. Failure developments that cannot be safely detected before reaching a critical state
  • C. both (a) and (b)
  • D. none of the above
Answer: C — both (a) and (b)
Bunkering and fuel supply arrangements must comply with statutory requirements for hazardous area separation, containment integrity, and rapid emergency isolation.

9. To ensure no release occurs during the hook-up or disconnect of any components during the bunkering process

  • A. draining of the bunker piping systems prior to connect or disconnect s necessary
  • B. gassing up of the bunker piping systems with LNG prior to connect or disconnect 5 necessary
  • C. purging of the bunker piping systems with inert gas prior to connect or disconne s recei
  • D. none of the above
Answer: B — gassing up of the bunker piping systems with LNG prior to connect or disconnect 5 necessary
To prevent accidental atmospheric releases during bunkering connection or disconnection, bunker manifolds must be inerted and verified gas-free before breaking flanges.

10. What is provided in bilge well in each tank connection space of an independent iqueted yes surge and

  • A. a level indicator
  • B. a temperature sensor
  • C. unsafety systems
  • D. both (a) and (b)
Answer: C — unsafety systems
Bilge wells in tank connection spaces of independent gas tanks are equipped with level sensors, temperature probes, and drainage arrangements to safely detect and evacuate any condensate or leakage.

11. Substance of cargo vapour in air which is not flammable

  • A. Ammonia
  • B. Methane
  • C. Chlonine
  • D. Propane
Answer: B — Methane
When fuel gas vapor is diluted with inert nitrogen such that the oxygen content is below the Limiting Oxygen Concentration (LOC), the mixture cannot ignite.

12. For engines fitted with ignition systems, when would the, correct operaton of the goon system on each unit shal be verified?

  • A. prior to admission of gas fuel
  • B. after admission of gas fuel
  • C. every three months
  • D. as time permits
Answer: A — prior to admission of gas fuel
On dual-fuel engines with pilot ignition, the correct operation and timing of the pilot fuel ignition system must be automatically verified on each cylinder prior to admitting gas fuel.

13. Stop valves shall be fitted in the water spray application main supply line:

  • A. At intervals not exceeding 35 metres, for the purpose of isolating damaged sections
  • B. At intervals not exceeding 45 metres, for the purpose of isolating damaged sections
  • C. At intervals not exceeding 50 metres, for the purpose of isolating damaged sections
  • D. At intervals not exceeding 40 metres, for the purpose of isolating damaged sections
Answer: D — At intervals not exceeding 40 metres, for the purpose of isolating damaged sections
Stop valves must be installed in the water spray main supply line at intervals not exceeding 40 meters to enable isolation of damaged pipe sections during a fire.

14. You should always check closed doors for before opening them

  • A. heat from fire.
  • B. paint
  • C. cleanliness
  • D. None of the above
Answer: A — heat from fire.
Before opening closed doors during a fire emergency, always check the door and handle for heat with the back of a gloved hand to avoid sudden backdrafts or exposing yourself to intense flames.

15. How is the gas detection required?

  • A. non-continuous with delay
  • B. continuous without delay
  • C. continuous with delay
  • D. non-continuoss without delay
Answer: A — non-continuous with delay
Gas detection systems in hazardous spaces, ducting, and engine rooms must provide continuous monitoring with rapid response times and immediate automated alarms.

16. Air locks provides __ _

  • A. free and easy passage
  • B. a deck area not less than 15 m2
  • C. both (a) and (b)
  • D. none of the above
Answer: C — both (a) and (b)
Air locks maintain an overpressure differential and provide a two-door interlocked vestibule that prevents flammable gas ingress from hazardous open decks into gas-safe spaces.

17. Ventilation systems is required to avoid __ _

  • A. gas accumulation
  • B. gas seperation
  • C. gas maintenance
  • D. none of the above
Answer: A — gas accumulation
Mechanical ventilation systems in gas fuel machinery spaces and double-wall piping are designed to run continuously to prevent any accumulation of flammable gas pockets.

18. What is the ventilation capacity of fuel preparaton rooms, pump and compressor rooms?

  • A. 30 air changes per hour
  • B. 30 air changes per sec
  • C. 30 air changes per min
  • D. 30 air changes per milli sec
Answer: A — 30 air changes per hour
The IGF Code mandates that fuel preparation rooms, compressor rooms, and pump rooms must be equipped with an independent mechanical extraction ventilation system providing at least 30 air changes per hour.

19. Fuel containment system and machinery spaces containing source that might release gas into the space shall be arranged and located such that

  • A. In case of fuel gas leakage it will not affect personnel
  • B. A fire or explosion in either will not lead to an unacceptable loss of power
  • C. Leakage will not affect accomodation area
  • D. There is no complete blackout
Answer: A — In case of fuel gas leakage it will not affect personnel
Under the IGF Code, fuel containment arrangements and machinery spaces containing gas sources must be isolated and protected so that any unintended fuel gas leakage is contained and will not directly endanger onboard personnel or living spaces.

20. Substance of cargo vapour in air which is not toxic

  • A. Propane
  • B. Ethylene
  • C. Methane
  • D. All the above
Answer: C — Methane
Pure methane vapor in air is a simple asphyxiant and is non-toxic, whereas other chemical gases and high concentrations of aromatic hydrocarbons present distinct physiological toxicity.

21. What is the use of tankscope?

  • A. An instrument used for measuring hydrocarbon vapour in inerted atmospheres
  • B. An instrument used for measuring carbon vapour in inerted atmospheres
  • C. An instrument used for measuring oxygen vapour in inerted atmospheres.
  • D. An instrument used for measuring dioxide vapour in inerted atmospheres
Answer: A — An instrument used for measuring hydrocarbon vapour in inerted atmospheres
A Tankscope is a specialized non-catalytic optical/thermal conductivity instrument specifically designed to measure hydrocarbon gas concentrations (0-100% volume) in inert nitrogen or flue-gas atmospheres where catalytic bead explosimeters cannot operate.

22. Risk assesment needs to be carried out and applied for

  • A. Sizing of drip trays
  • B. Design of airlocks
  • C. Liquefied gas containment system;
  • D. All af above
Answer: C — Liquefied gas containment system;
A formal risk assessment must be carried out for the design, material selection, and structural arrangement of the liquefied gas fuel containment system to evaluate all failure modes.

23. 1 sS Exam 25. During bunkering, an area of sufficient size that keeps other vessels, vehicles, equipment, and cargo operations far enough away so that they pose little risk of damaging or interfering with the LNG bunkering system and equipment is called:

  • A. Safety Zone
  • B. Security Zone
  • C. Hazardous Area
  • D. ISPS Border
Answer: A — Safety Zone
The bunkering safety zone is a designated perimeter around the bunkering manifold and fuel storage areas where unauthorized activities, hot work, and non-certified equipment are strictly prohibited.

24. In Overflow control, What will an additional sensor operating independently of the high liquid level alarm do?

  • A. automatically actuate a switchon valve
  • B. automatically actuate a shutoff valve
  • C. manually actuate a shutoff valve
  • D. manually actuate a switchon valve
Answer: B — automatically actuate a shutoff valve
In fuel tank overflow control systems, an independent high-high level sensor (operating independently of the 95% level alarm) automatically actuates the emergency shutoff valve to prevent overfilling.

25. As per the regulation, It shall be possible to empty, purge and vent fuel storage tanks with fuel piping systems. Prior to venting with dry air to avoid an explosion hazardous atmosphere in tanks and fuel pipes what should be performed?

  • A. Inerting shall be performed.
  • B. Gassing up shall be performed.
  • C. Cooling down should be performed.
  • D. none of the above
Answer: A — Inerting shall be performed.
Prior to aerating fuel tanks or fuel piping with dry air, thorough inerting with dry nitrogen must be performed to ensure the hydrocarbon concentration is reduced below the flammable range.

26. Accident Limit States (ALS) relevant design parameters of limit state design of fuel containment systems

  • A. correspond to the maximum load-carrying capacıty
  • B. correspond to degradation due to the effect of cyclic loading
  • C. concern the ability of the structure to resist accident situations
  • D. none of the above
Answer: C — concern the ability of the structure to resist accident situations
Accidental Limit States (ALS) criteria in fuel containment design assess structural resistance against abnormal collision, grounding, fire exposure, or cryogenic blast loading.

27. The bunkering system shall be so arranged that

  • A. No leakage takes place
  • B. No gas is discharged to the atmosphere during filling of storage tanks
  • C. The bunkering system withstands fluctuation in loading pressures
  • D. The bunkering system withstands fluctuation in ambient temperatures
Answer: B — No gas is discharged to the atmosphere during filling of storage tanks
The bunkering system must be designed so that no gas vapor is vented or discharged to the atmosphere during fuel storage tank filling operations, utilizing vapor return lines where necessary.

28. Electric equipment installed in explosion hazardous spaces and areas

  • A. Should have routine maintenance schedule as per PMS
  • B. Must be inspected and surveyed as per requiremnt of Adminstration
  • C. Should have the procedures and information regarding in-service survey, maintenance and resting
  • D. Should be intristically safe
Answer: B — Must be inspected and surveyed as per requiremnt of Adminstration
All electrical equipment installed in explosion-hazardous spaces must be certified safe (Ex-rated), documented in the hazardous area register, and regularly surveyed in accordance with Administration rules.

29. LNG in liquid state is :

  • A. highly flammable and easily ignite
  • B. not flammable and cannot ignite
  • C. not toxic and can ignite
  • D. none of the above
Answer: C — not toxic and can ignite
In its pure liquid state, LNG is non-toxic, clear, and non-corrosive, but it vaporizes rapidly into flammable methane gas that ignites readily when mixed with air within its flammability limits.

30. What will be the Emergency Shutdown protected machinery space fallure?

  • A. the spaces are considered gas safe under all conditions
  • B. a single failure cannot lead to release of fuel gas into the machinery space
  • C. a single failure may result in a gas release into the space
  • D. none of the above
Answer: A — the spaces are considered gas safe under all conditions
In ESD-protected machinery spaces, the space is deemed gas-safe under normal operation, but upon gas detection, electrical disconnection and fuel tripping occur to prevent explosive ignition.

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.

Set 7 — 1 BIGF exit exam questions with answers

1. What is concentration of a hydrocarbon gas in air below which there is insufficient hydrocarbon to support combustion?

  • A. Flash point
  • B. Gas freeing
  • C. Flammable range
  • D. Lower flamable limit
Answer: D — Lower flamable limit
The Lower Flammable Limit (LFL/LEL) represents the minimum volume percentage of fuel vapor in air required to support combustion; below this level the fuel mixture is too lean.

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