Assistant Engineer OSV Practice Test (OSE02)

The engineer-officer step on offshore supply vessels: motor plants, general subjects, safety, electrical. Coast Guard exam code OSE02.

277 real questions from the Coast Guard National Maritime Center's public sample exams, free. Each module needs 70% to pass.

Passing score: Coast Guard pass marks module by module, and the retest rules

What's free: daily rounds, the Brig, the drills and the Pass Meter, for every license. Your first module test is free too. After that, the full Exam Room is $19, once. No subscription.

What's on the test

Picture questions link to the drawing in the Coast Guard's free sample PDF. A few that need reference tables are left out.

10 sample questions

1. What statement concerning fuel cetane rating and the ignition delay period is true as it applies to offshore anchor handling vessel main propulsion diesel engines?

   • A.The ignition delay period is the lag in time between when fuel injection actually begins and when combustion actually begins, and the higher the cetane rating of the fuel the longer the ignition delay period.
   • B.The ignition delay period is the lag in time between when fuel injection actually begins and when combustion actually begins, and the higher the cetane rating of the fuel the shorter the ignition delay period.
   • C.The ignition delay period is the lag in time between when fuel injection is initiated and when fuel injection actually begins, and the higher the cetane rating of the fuel the longer the ignition delay period.
   • D.The ignition delay period is the lag in time between when fuel injection is initiated and when fuel injection actually begins, and the higher the cetane rating of the fuel the shorter the ignition delay period.
   Show answer

   B. The ignition delay period is the lag in time between when fuel injection actually begins and when combustion actually begins, and the higher the cetane rating of the fuel the shorter the ignition delay period.

   Q650, Assistant Engineer OSV: Motor Plants

2. Energy losses occurring in a hydraulic system are ultimately absorbed by the __________.

   • A.reservoir expansion chamber
   • B.atmosphere as heat
   • C.fluid as friction
   • D.hydraulic piping flexibility
   Show answer

   B. atmosphere as heat

   Q802, Electrician

3. Which extinguishing agent is the best for use on electrical fires?

   • A.Water fog
   • B.CO2
   • C.Dry chemical
   • D.Foam
   Show answer

   B. CO2

   Q451, Deck General / Safety

4. Which of the following voltage testers would be associated with high quality, be safe to use, and minimize the electric shock hazard?

   • A.a voltage tester with a high input impedance and a voltage rating higher than any expected measured voltages
   • B.a voltage tester with a low input impedance and a lower voltage rating than any expected measured voltages
   • C.a voltage tester with a low input impedance and a higher voltage rating than any expected measured voltages
   • D.a voltage tester with a high input impedance and a lower voltage rating than any expected measured voltages
   Show answer

   A. a voltage tester with a high input impedance and a voltage rating higher than any expected measured voltages

   Q801, Junior Engineer, Part II

5. In all diesel engines, including those used in offshore oil spill response vessels, at what point in the combustion cycle does ignition actually begin?

   • A.Near the completion of the compression event
   • B.Near the completion of the expansion (power) event
   • C.Near the completion of the scavenging event
   • D.At the beginning of the compression event
   Show answer

   A. Near the completion of the compression event

   Q650, Assistant Engineer OSV: Motor Plants

6. What is the pressure and condition of the refrigerant entering the receiver of a refrigeration system?

   • A.superheated high-pressure vapor
   • B.subcooled high-pressure liquid
   • C.superheated low-pressure vapor
   • D.subcooled low-pressure liquid
   Show answer

   B. subcooled high-pressure liquid

   Q803, Refrigerating Engineer

7. The advantage of using a dry chemical fire extinguishing agent is __________.

   • A.its excellent cooling ability
   • B.permanent extinguishment regardless of the reignition sources
   • C.its good stability and non-toxicity
   • D.all of the above
   Show answer

   C. its good stability and non-toxicity

   Q801, Junior Engineer, Part II

8. What is an ammeter used to measure?

   • A.circuit continuity
   • B.current flow in a circuit
   • C.the voltage between two points in a circuit
   • D.total or partial circuit resistance
   Show answer

   B. current flow in a circuit

   Q802, Electrician

9. Before shutting down the main propulsion engines on an offshore supply vessel, ideally what should be accomplished FIRST?

   • A.The engine should be operated at a steady, but substantial load for several minutes, then shut down.
   • B.The engine should be shut down immediately with no delay period, regardless of the engine load.
   • C.The engine should be operated at rated load for several minutes, then shut down.
   • D.The engine should be operated with the load removed from the engine for several minutes, then shut down.
   Show answer

   D. The engine should be operated with the load removed from the engine for several minutes, then shut down.

   Q650, Assistant Engineer OSV: Motor Plants

10. Before boring a blind tapered hole, a good shop practice to follow is to __________.

    • A.drill to the small diameter of the taper
    • B.drill to the large diameter of the taper
    • C.bore a straight hole
    • D.use a tapered reamer
    Show answer

    A. drill to the small diameter of the taper

    Q805, Oiler, Part II

What the study guide does

• Short daily rounds of 10 questions, with a streak.
• Practice tests built like the real one, scored with the real pass marks (first one free, then $19 once for the full Exam Room).
• The Brig: questions you miss come back until you get them right twice.
• Pass Meter: your chance of passing every module if you sat it today, worked out from your own answers.