Assistant Engineer – Limited, Revision & Practice Exams

In general, the thermal bulb for a thermal expansion valve used in a reciprocating air conditioning system is usually charged with what substance?

1. bees wax
2. distilled water
3. the same refrigerant as the system ✓
4. mercuric sulfate

A two-element boiler feedwater regulator is controlled by __________.

1. steam flow and feedwater flow
2. drum water level and feedwater flow
3. steam flow and drum water level ✓
4. drum water level and drum pressure

Which of the conditions listed could prevent a centrifugal condensate pump from developing its rated capacity?

1. Venting the pump to the vacuum side of the condenser.
2. Flooding of the main condenser hotwell.
3. Closing the water seal line to the packing gland. ✓
4. Operating the pump with a positive suction head.

The minimum temperature requirements for fuel oil in storage tanks is related to the _________.

1. pumpability of the oil ✓
2. size of the containment area in case of overflow
3. fire point of the oil
4. size of the vents

Compared to the return flow oil burner system, an internally mixed steam atomizer requires __________.

1. less excess air ✓
2. higher fuel oil viscosity
3. higher air velocity
4. greater turbulence in the air/oil stream

Which of the following operational practices is helpful in avoiding the accumulation of condensate in the main reduction gear casing?

1. The temperature of the lubricating oil should not exceed the gear manufacturer's recommendation when the unit is operating at full load.
2. Avoid applying gland sealing steam to the low-pressure turbine until you are ready to start up the first stage air ejector.
3. Always ensure that the lubricating oil pressure is 14-17 psi when operating in unusually cold waters.
4. After the main unit is secured, lubricating oil should be circulated until the temperature of the oil and reduction gear casing approximates the engine room temperature. ✓

Because of the close tolerances used in diesel engine fuel oil pumps, a worn plunger requires __________.

1. grinding the spare plunger to the barrel
2. replacing the plunger and the barrel ✓
3. highly polishing both the plunger and barrel
4. replacing plunger only

The most common contaminate of governor hydraulic fluid is __________.

1. moisture
2. dirt ✓
3. air
4. acid

A photoelectric cell installed in an automatically fired auxiliary boiler burner management system __________.

1. opens the burner circuit upon sensing a flame failure ✓
2. detects a flame failure by monitoring radiant heat from glowing refractory
3. requires mechanical linkage to secure the burner fuel supply
4. must be bypassed at low firing rates

A variable capacity, pressure atomizing, fuel oil burner functions to __________.

1. maintain a constant fuel temperature
2. provide a wide range of combustion ✓
3. provide a constant fuel return pressure
4. maintain smokeless fuel oil atomization

The pressuretrol which is installed on an auxiliary boiler senses steam pressure changes and __________.

1. controls the flow of feedwater to the boiler
2. monitors the boiler high water level
3. secures the fires when a fusible plug burns out
4. automatically regulates the quantity of oil and air flow to the burner ✓

While air is being compressed in a centrifugal flow gas turbine, what happens to the direction of air flow?

1. Changes only at the compressor discharge.
2. Changes only at the compressor inlet.
3. Changes at each separate component. ✓
4. Changes only once from inlet to outlet.

An axial compressor basically consists of which of the following?

1. Rotating pistons and stationary liners.
2. Stationary vanes and rotating blades. ✓
3. A rotating impeller and a stationary diffuser.
4. A stationary impeller and a rotating diffuser.

What is the term used to describe the stationary vanes preceding the first stage of an axial compressor?

1. Variable stator vanes.
2. Inlet guide vanes. ✓
3. First stage stator vanes.
4. Variable inlet vanes.

A centrifugal flow gas turbine uses what type of combustion chamber?

1. can ✓
2. annular
3. can-annular
4. double-annular

The circle of turbine stationary vanes that convert pressure and thermal energy to velocity energy and direct the combustion gases in the direction of turbine wheel rotation is referred to as what?

1. Nozzle assembly. ✓
2. Diffuser assembly.
3. Rotor assembly.
4. Compressor assembly.

What are the two principal functions of the turbine nozzle guide vanes?

1. Convert the potential energy of the hot gases into heat energy and direct the flow of gases to the turbine rotor blades.
2. Convert the heat energy of the hot gases into potential energy and direct the flow of gases to the turbine rotor blades.
3. Convert the heat energy of the hot gases into potential energy and direct the flow of gases to the compressor rotor blades.
4. Convert the heat energy of the hot gases into kinetic energy and direct the flow of gases to the turbine rotor blades. ✓

How is the lube oil supplied to each bearing in a gas turbine engine controlled?

1. Flow divider.
2. Lube oil pump.
3. Calibrated orifice. ✓
4. Regulating valve.

The wooden plug fitted tightly in the vent of a damaged tank may prevent the tank from __________.

1. collapsing
2. developing free surface moments
3. developing free surfaces
4. filling completely ✓

Paints and solvents used aboard a vessel should be __________.

1. stowed safely at the work site until work is completed
2. covered with a fine mesh screen to protect from ignition sources
3. returned to the paint locker after each use ✓
4. drained into a common container after each use

A simple precaution to reduce the possibility of accidental fires in the paint locker, is to __________.

1. label the fixed firefighting system
2. store paint cans on metal shelves only
3. not allow oily rags to accumulate in the space ✓
4. place a portable fire extinguisher immediately outside the locker

The longer an oil fire is permitted to burn, the __________.

1. easier it is to control
2. easier it is to extinguish
3. harder it is to extinguish ✓
4. less chance there is of reignition

How are fuses usually rated?

1. watts only
2. amps only
3. volts and amps only
4. volts, amps, and interrupting capacity ✓

Modern ships use multiple computers arranged in a client/server network to perform various shipboard functions. What type of computer network would most likely be used aboard ship?

1. Wireless local area network
2. Wireless wide area network
3. Wired wide area network
4. Wired local area network ✓

Before any work on electrical or electronic equipment is performed, which of the following precautions should be carried out?

1. Station a man at the circuit supply switch.
2. Secure and tag the supply circuit breaker in the open position. ✓
3. De-energize the applicable switchboard bus.
4. Bypass the interlocks.

Before any auxiliary diesel engine hydraulic starting system is opened for servicing or repair, you must __________.

1. Place all control levers in the "HOLD" position
2. Ensure that the hydraulic fluid reservoir is full
3. Block all hydraulic hoses using high-pressure covers
4. Bleed off all hydraulic pressure from the system ✓

Starting a large low-speed propulsion diesel engine on diesel fuel during cold weather conditions will be made easier by __________.

1. increasing the quantity of starting air
2. increasing the lube oil pressure
3. heating the engine fuel supply
4. heating the engine coolant ✓

Which of the following statements is true concerning the cetane number of diesel fuel?

1. The cetane number affects the amount of injection lag.
2. The cetane number is an indication of the fuel's viscosity.
3. Ignition lag is reduced with fuels having a high cetane number. ✓
4. The cetane number is of little significance in the combustion process.

Compared to a naturally aspirated diesel engine, a supercharged diesel engine has __________.

1. a cylinder air charge of higher pressure ✓
2. reduced cylinder mean effective pressure
3. less valve overlap
4. reduced blow-by

In a naturally aspirated diesel engine, the volume of air intake is directly associated with engine __________.

1. compression ratio
2. displacement ✓
3. fuel pressure
4. cylinder clearance volume

In a diesel engine exhaust system, the cooling of the exhaust gases below their dew point, will result in __________.

1. increased engine back pressure
2. sulfuric acid corrosion ✓
3. surface pitting of the turbocharger compressor blades
4. moisture impingement on the turbocharger compressor blading

A water jacket is placed around the exhaust manifolds of propulsion diesel engines to __________.

1. Reduce heat radiation to the engine room ✓
2. Aid in preventing turbocharger overheating
3. Condense and drain moisture from exhaust gases
4. Dampen exhaust gas pulsations in the manifold

An open cycle gas turbine engine is best described by which of the following statements?

1. Energy is neither created nor destroyed and the cycle is therefore perpetual.
2. Working fluids are taken in, transformed, and then recuperated.
3. Working fluids are taken in, transformed, and then discarded. ✓
4. Energy is added externally.

The canopy of your life raft should __________.

1. go into place as the raft is inflated ✓
2. be put up after everyone is aboard
3. be put up only in severe weather
4. be used as a sail if the wind is blowing

Which of the gases listed is the poisonous gas most likely to be found in a closed compartment involved in a fire?

1. Nitrogen
2. Hydrogen
3. Carbon dioxide
4. Carbon monoxide ✓

When required to work in an area where explosive gases may accumulate, you should use hand tools which are __________.

1. approved by the Coast Guard
2. high carbon steel
3. non-ferrous ✓
4. fixed with a ferrous cover

When compared to other fire extinguishing agents, water fog __________.

1. has the greatest ability to produce foam
2. has the greatest cooling ability ✓
3. will completely remove toxic fumes from the air
4. will completely remove combustible vapors from the air

Annual servicing of a hand portable CO2 fire extinguisher includes __________.

1. Weighing the cylinder and recharging if weight loss exceeds 10% of the weight of the charge ✓
2. Inspecting the pressure gauge to ensure the needle is within operating range
3. Hydrostatic testing of the cylinder
4. Discharging, cleaning inside, and recharging

Both the direction of flow and fluid flow rate of a variable displacement radial piston pump are determined by the relative positions of the __________.

1. floating ring and pump shaft
2. floating ring and cylinder body ✓
3. pump shaft and horizontal ports
4. pump shaft and central valve

What is the primary purpose of the lead-lag arrangement of the two potable water pumps supporting a typical potable water system?

1. Enabling the lead pump to pump against a shut-off head during periods of relatively low demand and the lag pump to recirculate when the demand is high.
2. Enabling both potable water pumps to cycle on and off together in response to system demand changes.
3. Enabling the lead pump to cycle on and off during periods of relatively low demand and the lag pump to assist the lead pump only when the demand is high. ✓
4. Enabling the lag pump to cycle on and off during periods of relatively low demand and the lead pump to assist the lag pump only when the demand is high.

A vessel is in compliance with federal regulations regarding the discharge of sewage by __________.

1. treating sewage in an approved system
2. holding all sewage onboard
3. pumping the sewage ashore to an approved container
4. all of the above ✓

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

1. trapezoid
2. square
3. circle
4. triangle ✓

How can the loss of residual magnetism in an alternator with a brushless excitation system be corrected?

1. using a storage battery or battery charger to "flash" the field ✓
2. running the generator at normal speed with the field rheostat fully counterclockwise
3. allowing the generator to run at 10% of normal speed for 5 minutes
4. running the rotor in the opposite direction for 5 minutes

How is the difference between the synchronous speed of a three-phase induction motor and its operating speed correctly expressed?

1. deviation
2. a decimal fraction of full load speed
3. slip ✓
4. a percent of full load speed

What type of AC motor would use a rheostat in the rotor circuit to vary the speed of the motor?

1. wound-rotor induction motor ✓
2. synchronous motor
3. regenerative braking motor
4. squirrel-cage induction motor

Of the following, what shipboard system is MOST likely to use the synchronous transmission system featuring a transmitter and receiver?

1. Shaft revolution indicator system
2. Turbocharger RPM indicator system
3. Centrifuge RPM indicator system
4. Rudder angle indicator system ✓

If it becomes absolutely necessary to run an alternator at lower than 5% below its rated frequency, in terms of output voltage, what must be done?

1. The alternator output voltage must be increased proportionately upward to compensate for the frequency decrease.
2. The alternator output voltage must be decreased proportionately downward with the frequency decrease. ✓
3. The alternator output voltage must be maintained at the rated value for the alternator output voltage.
4. Under no circumstances is it permissible to run an alternator at a frequency lower than 5% below its rated frequency.

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

1. a voltage tester with a high input impedance and a voltage rating higher than any expected measured voltages ✓
2. a voltage tester with a high input impedance and a lower voltage rating than any expected measured voltages
3. a voltage tester with a low input impedance and a higher voltage rating than any expected measured voltages
4. a voltage tester with a low input impedance and a lower voltage rating than any expected measured voltages

Where is the "dry pipe" located in a boiler?

1. Behind the superheater screen tubes
2. In the top of the steam drum ✓
3. Below the generation tube bank
4. At the superheater outlet

Scavenging air is supplied to steam sootblower elements to __________.

1. Prevent back up of combustion gases into sootblower heads ✓
2. Prevent buildup of soot on the element
3. Prevent overheating of adjacent tubing
4. Provide cooling air when sootblower elements are rotating through blowing arcs

In a boiler equipped with a convection type superheater, the superheater tubes are located __________.

1. In a position screened from the furnace ✓
2. Between the downtake nipple and circulator tube
3. Between the economizer and generating tubes
4. In the path of the radiant heat of combustion

Before blowing tubes in a boiler equipped with steam sootblowers, you should __________.

1. Increase the boiler water level ✓
2. Lower the boiler steam pressure
3. Reduce the forced draft fan speed
4. Decrease the boiler water level

The two-element feedwater regulator functions similarly to the three-element feedwater regulator, but does not utilize __________.

1. drum pressure
2. water level
3. steam flow measurement
4. feedwater flow measurement ✓

What is meant by the term independent bilge suction?

1. The means by which the machinery space bilge is pumped out by a pump not normally used as a bilge pump but using either bilge manifolds or automatic bilge suction valves.
2. The means by which a cargo-hold bilge is pumped out by a pump normally used as a bilge pump but independent of any bilge manifolds or automatic bilge suction valves.
3. The means by which a cargo-hold bilge is pumped out by a pump not normally used as a bilge pump but using either bilge manifolds or automatic bilge suction valves.
4. The means by which the machinery space bilge is pumped out by a pump normally used as a bilge pump but independent of any bilge manifolds or automatic bilge suction valves. ✓

With regard to a ballast system associated with a dry cargo ship, what is the primary purpose of the fore peak and aft peak tanks?

1. Correcting a condition of hogging or sagging of the vessel
2. Adjusting the overall draft of the vessel
3. Correcting a list condition on the vessel
4. Adjusting the trim of the vessel ✓

Aftercoolers are used with air compressors to __________.

1. dampen pressure pulses in the discharge air
2. ensure complete expansion of the compressed air
3. decrease the density of compressed air
4. reduce the temperature of compressed air ✓

Which of the following statements represents the proper procedural sequence for adjusting the metering rate of an in-line lubricator as used in a ship's service air system hose station? Assume that the pressure regulator has been properly set.

1. Establish normal air flow. Determine drip rate. Further open needle valve to increase drip rate or further close needle valve to decrease drip rate, as appropriate. ✓
2. Establish normal air flow. Determine drip rate. Further open needle valve to decrease drip rate or further close needle valve to increase drip rate, as appropriate.
3. Temporarily shut-off air flow. Determine drip rate. Further open needle valve to increase drip rate or further close needle valve to decrease drip rate, as appropriate. Re-establish normal air flow.
4. Temporarily shut-off air flow. Determine drip rate. Further open needle valve to decrease drip rate or further close needle valve to increase drip rate, as appropriate. Re-establish normal air flow.