Third Assistant Engineer Practice Test (3AE02)

The other half of the Third Assistant Engineer exam: general subjects, electrical and controls, and two steam plant modules. Coast Guard exam code 3AE02.

275 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 is true concerning the effect of elevating the temperature of the oily-water mixture associated with an oily-water separator?

   • A.Heating the oily-water mixture decreases the viscosity of the oil and increases the specific gravity differential between the oil and water.
   • B.Heating the oily-water mixture increases the viscosity of the oil and increases the specific gravity differential between the oil and water.
   • C.Heating the oily-water mixture increases the viscosity of the oil and decreases the specific gravity differential between the oil and water.
   • D.Heating the oily-water mixture decreases the viscosity of the oil and decreases the specific gravity differential between the oil and water.
   Show answer

   A. Heating the oily-water mixture decreases the viscosity of the oil and increases the specific gravity differential between the oil and water.

   Q801, Junior Engineer, Part II

2. In order for a live-line tester to be used to test and prove dead a high voltage circuit, what must be done to verify the ability of the tester to detect a voltage?

   • A.The live-line tester need not be checked prior to testing the circuit to be worked upon as long as it has not been declared inoperative.
   • B.The live-line tester should be checked by connecting to a known high voltage source before and after the circuit to be worked upon is tested.
   • C.The live-line tester should be checked by connecting to a known high voltage source only after testing the circuit to be worked upon.
   • D.The live-line tester should be checked by connecting to a known high voltage source only before testing the circuit to be worked upon.
   Show answer

   B. The live-line tester should be checked by connecting to a known high voltage source before and after the circuit to be worked upon is tested.

   Q604, Chief Engineer Limited: Electrical, Electronics & Control

3. Which of the following would indicate a moderate leak in the desuperheater?

   • A.Lower than normal fuel oil consumption
   • B.Lower than normal auxiliary steam temperature
   • C.Higher than normal fuel oil consumption
   • D.Higher than normal auxiliary steam pressure
   Show answer

   B. Lower than normal auxiliary steam temperature

   Q605, Chief Engineer Limited: Steam Plants

4. Which of the filters listed will deplete the additives in lubricating oil?

   • A.Extended area membrane filter
   • B.Cloth bag extractor
   • C.Absorbent filter
   • D.Adsorbent filter
   Show answer

   D. Adsorbent filter

   Q800, Junior Engineer, Part I

5. A centrifugal pump gradually develops insufficient discharge pressure. What corrective action is required?

   • A.Throttle in on the discharge valve.
   • B.Replace the lantern rings.
   • C.Throttle in on the suction valve.
   • D.Replace the wearing rings.
   Show answer

   D. Replace the wearing rings.

   Q808, Pump Technician

6. What is the shape of the schematic symbol for an operational amplifier used in an analog circuit?

   • A.circle
   • B.trapezoid
   • C.triangle
   • D.square
   Show answer

   C. triangle

   Q615, Assistant Engineer Limited: Electrical, Electronics & Control

7. When vapor is in contact with and remains at the same temperature as the boiling liquid from which it was generated, the vapor and liquid are said to be in which of the following?

   • A.critical state
   • B.saturated condition
   • C.latent contact
   • D.sensible contact
   Show answer

   B. saturated condition

   Q611, Assistant Engineer Limited: Steam Plants

8. Lube oil pumps taking suction from the sump of most small marine engines are usually __________.

   • A.diaphragm type
   • B.eductor type
   • C.centrifugal type
   • D.positive displacement type
   Show answer

   D. positive displacement type

   Q804, Oiler, Part I

9. Concerning a conventional mooring winch, what statement is true?

   • A.A high-capacity brake is required to hold a load approaching the breaking strength of the mooring line, but it is required to slip at a lower tension to avoid mooring line breakage.
   • B.A high-capacity brake is required to hold a load equal to the breaking strength of the mooring line. For reasons of safety, no slippage of the brake is permitted.
   • C.A high-capacity brake is required to hold a load exceeding the breaking strength of the mooring line. For reasons of safety, no slippage of the brake is permitted.
   • D.A low-capacity brake is required to hold a load far below the breaking strength of the mooring line, but it is required to slip at a lower tension to avoid mooring line breakage.
   Show answer

   A. A high-capacity brake is required to hold a load approaching the breaking strength of the mooring line, but it is required to slip at a lower tension to avoid mooring line breakage.

   Q601, Chief Engineer Limited: General Subjects

10. What condition associated with a lead-acid battery cell can cause the plates to partially short-out and cause the cell to fail to hold a charge?

    • A.dirty or acid-wet tops and sides of batteries
    • B.sulfation of the plates due to consistent undercharging or leaving the battery in a discharged state
    • C.accumulation of sediment within the cells due to excessive overcharging and discharging
    • D.lime accumulation on both the positive and negative terminal posts
    Show answer

    C. accumulation of sediment within the cells due to excessive overcharging and discharging

    Q615, Assistant Engineer Limited: Electrical, Electronics & Control

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.