Le test comprend 80 questions aléatoires.
Total de questions sur ce sujet : 118
Which of the options given is likely to be the reason for a drop in the charge air manifold pressure of a diesel engine operating with an exhaust gas turbocharger?
Insufficient cooling of the charge air.
Engine room exhaust fans stopped.
Exhaust gas boiler fouled.
Continuity testing of a delta connected three phase induction motor yields the following results; U1-V1 = 4 Ohms, V1-W1 = 4 Ohms, W1-U1 = 4 Ohms. What is the value of continuity resistance for each winding i. e. U1-U2?
After a couple of hours of operation the failure alarm sounds for a heavier fuel oil purifier which is operating on a timed automatic sludge cycle. Upon investigation the purifier is found to be running slowly and when opened up the casing and sludge outlet is heavily fouled with sludge in contact with the bowl. From the options given what is the most likely cause of this problem?
The heavy fuel is unstable leading to excessive high viscosity sludge formation.
The dirty oil throughput is excessive.
The clutch for the drive shaft is worn and slipping.
The purifier bowl has not closed properly.
What is the maximum current that a 15 Volt, 3 Watt Zenerdiode can handle without damage?
When selecting switchgear to work with High Voltage it is important to use an appropriate arcing medium. What is meant by arcing medium?
The gas, liquid or vapor, which will minimize creation of an electric arc as contacts open.
Equipment, which communicates information about the arcing.
A material, which assists a welding process.
Who is responsible for ensuring that your ship’s security plan meets the requirements of the ISPS Code?
Recognized Security Organization.
Flag State Administration.
Company Security Officer.
A two step controller (open/close) has failed and the only available spare controller is a P+I controller. Select, from the options given, how the P+I controller could be set up to achieve approximate two step control.
Set the proportional band to maximum width and the integral action to minimum (repeats per minute).
Set the proportional band to minimum width and the integral action to minimum (repeats per minute).
Set the proportional band to minimum width and the integral action to maximum (repeats per minute).
Set the proportional band to maximum width and the integral action to maximum (repeats per minute).
In terms of automated control systems, what is typical for a continuous control system?
It is possible to predict the control mathematically.
The control valve will always be changing position.
It is not possible to have a stable process.
The output signal is equal to the input signal.
Which of the following options would be a typical differential pressure setting for a main engine slow down in the event of jacket cooling water system low flow?
When considering instrumentation systems, what is a typical symptom of a fault with the span of an instrument?
100 % output is accurate, but Zero-point is wrong.
Zero-point and 100 % are correct, but not at mid-range.
Zero-point is accurate, but 100 % input is not giving 100 % output.
A transformer overheats while taking a shore supply. Which is the likely cause?
The pyrotechnics used to transmit visual signals to other vessels, boats or aircrafts are of the following type:
All of the below mentioned.
A 250 V contactor has been fitted to a 220 V supply. Which of the following symptoms might be observed?
Contactor chattering (vibrating).
A draw card obtained from a cylinder of a large 2 stroke diesel engine shows that both cylinder compression and maximum pressures are low. Cards from other cylinders indicate normal operation. What is the likely cause of this problem?
Faulty cylinder component (piston rings, liner, etc.).
Excessive cooling of the charge air.
Faulty high pressure fuel pump.
What kind of electrolyte is used for Nickel-iron batteries?
Solution of sodium and water.
Solution of zinc-carbon and water.
Solution of sulphuric acid and water.
Solution of potassium hydroxide (KOH) and water.
A 3-phase cage rotor induction motor requires protection by a time delay overload trip. What is the reason for this?
It will allow for inrush current, or motor specific faults.
It will tolerate fault conditions during start up.
When performing electrical testing of a three phase motor, insulation resistance measurements may be influenced by which of the following?
Temperature, humidity and surface contamination.
Humidity, frequency and dampness.
Humidity, pressure and surface contamination.
Between 0,1 micro Ohm and 1,0 micro Ohm.
How will continuous low load operation influence the time between overhauls, tbo, for the cylinder covers and associated valves of a 4-stroke diesel engine?
Reduce the time between overhauls due to increasing fouling.
Increase the time between overhauls since the engine is not working as hard.
Increase the time between overhauls since fuel injectors work better at low load so combustion will be improved and the maintenance will be reduced.
Routine maintenance insulation testing of a three-phase induction motor should cover which measurements?
U1-U2, V1-V2, W1-W2, U-E, V-E, W-E.
U-E, V-E, W-E, U-V, V-W, W-U.
Which of the following symptoms would indicate that the filter drier in a refrigeration circuit has become blocked?
A large temperature drop across the drier.
A hammering noise from the compressors.
A hammering noise from the drier.
A pressure rise before the drier.
What is the best method for ensuring that the cylinder powers of a high speed diesel engine, fitted with a monoblock multi-cylinder fuel pump, are correctly balanced?
Have the fuel pump phased and calibrated in a test workshop.
Check the exhaust temperatures on each cylinder to see if they are equal.
Measure the maximum pressure of each cylinder to check that they are equal.
Take a set of indicator cards using a mechanical indicator and calculate the cylinder powers.
Why is it important that the correct tension is maintained in a diesel engine timing chain?
Correct tension ensures that the chain and associated equipment is within normal loading limits.
Correct tension ensures that there is absolutely no vibration in the chain.
Correct tension ensures that the fuel and valve timing are correct.
Correct tension ensures that the chain is correctly lubricated.
What principle of measurement are viscosity controllers usually based on?
Measurement of differential pressure.
Measurement of two different temperatures.
Measurement of temperature.
Which is the preferred method for starting an air conditioning refrigeration compressor which has been shut down for a period of time?
Start with suction valve throttled in to minimise risk of drawing liquid refrigerant into the compressor.
Start with all system valves fully opened.
Start and stop repeatedly until suction pressure and oil pressure are normal.
Start with the discharge valve throttled in to prevent excess condenser pressure.
Oil analysis results for a sample of diesel engine lubricating oil show a high level of tin. What could be the possible cause?
Debris from damage to a white metal bearing.
Debris from damage to a rolling contact bearing.
Cylinder oil contamination of the lubricating oil system.
Debris from fretting between bearing housing parts.
A transformer overheats while taking a shore supply. Which is the likely cause?
How can a lead-acid type battery be checked to confirm if it is fully charged or not?
Measure the relative density (specific gravity) of the electrolyte.
Measure the battery voltage.
Measure the level of the electrolyte.
Measure the temperature of the electrolyte.
How does the maximum oil film pressure in a white metal journal bearing operating under full fluid film conditions compare with the pressure of the lubricating oil supply system?
The pressure is greater than the pressure in the lubricating system and varies with the journal load.
The pressure is the same as the pressure in the lubricating system regardless of the journal load.
The pressure is greater than the pressure in the lubrication and is constant regardless of the journal load.
The pressure is less than the pressure in the lubricating system and varies with the journal load.
In what kind of measuring equipment might we find a Bourdon-tube?
In a pressure transmitter.
In a temperature transmitter.
This figure shows a transformer, with two windings, N(1) = 2 000 and N(2) = 1 000 turns, on a common magnetic circuit. Assume that there is no energy loss in the transformer itself. Calculate the current I(2) when the current I(1) = 2 A.
A medium speed diesel engine which is supported on a steel chocking system has had repeated problems with two of the chocks at the end of the engine on the port side becoming slack. This has led to some fretting damage to the bedplate and tank top in that area. What action should be taken to affect a cost effective permanent repair?
Tighten the holding down bolts in that area to 150 % recommended load to prevent further slackening and fretting.
Replace the complete steel chocking system with one using resilient mounts to accommodate movement and avoid further incidents of fretting.
Replace the damaged chocks with resin based chocks of an appropriate size.
Replace the complete steel chocking system with a resin based system.
When considering instrumentation systems, what is a typical symptom of a fault with the span of an instrument?
100 % output is accurate, but Zero-point is wrong.
Zero-point and 100 % are correct, but not at mid-range.
Zero-point is accurate, but 100 % input is not giving 100 % output.
What is the result of an “unusually large metacentric height”?
The vessel will roll slowly or be unstable.
The vessel will have a great bending moment.
The vessel’s tweendeck heights is too high.
The vessel will roll violently.
It is the Master’s responsibility to ensure that:
Concerned personnel carry out the on-board training programme effectively.
All information regarding the onboard training is given to the ship manager.
Safety equipment is not used during the training.
Life jackets are worn during every training.
Why is an automatic slow turning feature included in the start air system of many large 2 stroke diesel engines?
To avoid damage during start of the engine in case water or other liquid has gathered in the cylinders during an extended stop.
To reduce the start air consumption during start up of the engine.
To check that all indicator cocks are closed before starting engine.
To fill the cylinders with sufficient fresh air to ensure a safe start of the engine.
How is a Safety Management Certificate obtained?
Ship owner has Document of Compliance issued, and vessel is assessed and holds all statutory certificates.
RSS issue SMC with Register.
Vessel is surveyed by MCA and certificate issued.
Ship owner is authorised to carry out internal audits and issue SMC.
Power is available at a three-phase motor starter, but nothing happens (at starter or motor) when the start button is operated. Which of the following is a likely cause?
Open circuit in one of the motor cables.
Faulty overcurrent relay.
Which personnel must undergo familiarization training on board?
What does ISM stand for?
The International Management Code for the Safe Operation of Ships and for Pollution Prevention.
International Ship Measurement and Pollution Control.
International Safe Manning Certification.
Internal Ship Safety Management.
What is the advantage of a transmitter with a narrow measurement range?
Do not need any calibration.
Better linearity and increased accuracy.
The torsion meter for the main propeller shaft is reading high. The torque is sensed using the angle of twist principle with two clamp rings attached to the shaft at a fixed distance, with stationary proximity switches for measuring the angle of twist and also shaft speed fixed to a rigid stool. What is the most likely cause of the high reading?
Circumferential slip of the after clamp ring in the opposite direction to shaft rotation.
Axial slip of one of the clamp rings to bring them closer together.
Axial slip of one of the clamp rings to move them further apart.
In the circuit diagram shown the starter connects between which terminals?
A transformer rated at 22 kVA, 440/220 Volts, 60 Hz, is used to step down the voltage to a lighting system. The low tension voltage is to be kept constant at 220 Volts. What load impedance connected to the low-tension side will cause the transformer to be fully loaded?
Two reference points for pressure exist, absolute zero and atmospheric pressure. What are pressures measured relative to absolute zero called:
Which of the following is typical for a feed-forward control system?
Mathematical calculation of the system response.
Easy to obtain a perfect control.
Control of the process inlet side.
The process continually oscillates.
The fuel consumption for the main diesel engine has gradually increased over a period of a few months. All system pressures and temperatures appear normal. From the options given, choose the one which is the most likely cause of this:
Sea water temperature changing.
A portable oxygen analyser for use onboard ship is of the paramagnetic sensing element type. It is being used to test the atmosphere of a space onboard ship but starts to give erratic readings. There is no obvious indication as to why this is happening. Select from the options given the most likely cause of this problem:
The sampling filter is partially blocked giving rise to wide pressure variations in the sampling chamber.
The battery power is low.
Nitrogen gas is present in the atmosphere.
The sampling filter is blocked preventing gas from entering the sampling camber.
When starting air is applied to a diesel engine the engine fails to turn over but is seen to oscillate back and forth. What is the most likely cause of this problem?
One or more cylinder air start valves are stuck open.
Starting air pressure is too low.
An interlock is blocking the air to the starting air distributor.
The automatic valve has failed to open.
In which of the following automated control processes will the time constant be of minor importance?
Which one of the listed requirements regarding abandon ship drills corresponds to present SOLAS regulation?
Each lifeboat shall be launched, and maneuvered in the water with its assigned crew at least once every three months during an abandon ship drill.
Drills shall be conducted when the ship is in a harbour.
All lifeboats shall be lowered during drills.
What should be the healthy continuity resistance of a 220 V, 2,2 kW, 10 A heating element, when checked near to it’s rated operating temperature?
The main engine is running steady with an average exhaust gas temperature of approximately 350 °C. What would be a typical alarm/slow down setting for the cylinder exhaust gas temperature deviation from the average?
The cold room temperature is almost at the cut out point in a vapour-compression refrigeration system. What should the refrigerant state be just after the evaporator if the system is correctly set up?
Wet vapour at high pressure.
Cold liquid at high pressure.
Sub-cooled liquid at low pressure.
Slightly superheated low pressure gas.
What type of dynamic forces may cause indent in plating on forecastle deck and main deck in way of pillars inside forecastle?
Pressure forces caused by green water on deck.
Impact pressure forces in way of abrupt or flared bow.
Forces created by waves on the forecastle.
Slamming in way of flat bottom forward of light draught.
When work must be done on High Voltage equipment, it is vital that the equipment is earthed (grounded) after isolation procedures have been carried out. Why is this?
To provide a reference point, and so ensure accuracy of any test results.
To ensure that it is dead, even if there was a flaw in the isolation procedure.
To ensure that no energy remains in the system, and that it cannot be recharged by external influences.
To ensure that the equipment does not overheat due to currents circulating through earth (ground).
A cable has a resistance of 100 milli-ohms. It supplies a 300 A load over a distance of 100 meters. What is the voltage drop along it’s length?
The engine turns over normally when starting air is supplied but does not fire even though normal starting rpm is achieved. What could be the probable cause to this?
Air in the fuel oil system.
The lubricating oil temperature is low.
The turbocharger has not run up to normal full speed.
The turning gear interlock has operated.
When starting three phase induction motors there is sometimes a need to use a star-delta starter. A star-delta starter exhibits the following characteristics while connected in a star.
Reduced current and increased voltage.
Reduced current and reduced torque.
Increased current and power.
Reduced current and increased speed.
In case of a pollution in US waters, who shall notify the cleaning up contractor (OPA-90)?
A motor nameplate reads 75 hp. What is the reading in kW?
When measuring level of liquids with a conductivity level indicator, measurement is performed by:
Low voltage ships tend to have insulated neutral systems. What is the reason for this?
In the event of an earth fault vital equipment will not trip.
It’s easier to detect faults.
If the neutral is not insulated, then it may short to other conductors.
It’s more effective than insulating the live conductor.
A galley hot plate uses a Nichrome/Magnesium Oxide heating element, and is to be tested before being put into service for the first time. An insulation resistance test yields a reading of 0,3 M Ohm. Which action should be taken?
Put the element into service.
Wash the element in a degreaser agent. Then retest, and if ok put it into service.
Apply reduced voltage to the element for a few minutes. Then retest, and if ok put into service.
Some automated control systems use a master controller and a slave controller. What is the meaning of “remote mode” related to a slave controller?
The slave controller can be turned by a hand carried remote controller.
The slave controller can be in any mode of operation.
The slave controller receives the set-point from the output signal of the master controller.
The slave controller can be turned from the engine control room.
A triac is used to provide temperature control of an oven. The galley complains that the oven only reaches approximately 50 % of demanded temperature. Which of the following is a likely cause?
The triac has completely failed.
The voltage supply to the oven controller is reduced by about 50 %.
Connection between the demand knob and the triac gate terminal has gone open circuit.
One of the main switching elements in the triac has failed.
Some ships generate electrical power at 440 Volts, but then step up this voltage to supply specific electrical equipment. One common example, may be to feed a large bow thruster. Why is this done?
A large bow thruster will draw very large currents at low voltage. Being typically remote from the generator, significant voltage drops would occur at low voltage.
The shipyard could not purchase High Voltage generating plant at the time of manufacture, so they used what was available at the time.
The overall ship’s electrical load does not justify High Voltage generating plant. This method allows more power to be delivered to the bow thruster at low running cost.
Manufacturers can supply High Voltage bow thrusters at less cost, and the power factor is improved.
Worn piston rings are allowing a small amount of piston blow-by on a 2-stroke main diesel engine cylinder, but due to the circumstances, it is not possible to stop and do a piston overhaul. What is the correct, temporary action to take?
Increase cylinder oil feed rate slightly and monitor the scavenge space drains.
Continue to operate the engine as normal.
Increase cylinder oil feed rate to the maximum.
The circuit diagrams illustrate four different methods of wiring between a Pt 100 temperature sensor and its signal processing electronics. Which of the wiring methods gives the best measuring accuracy?
Why shall a duly qualified officer supervise any potential polluting operation?
To inform the authorities.
The operating mode of a pyrotechnic signal depends essentially on:
Instructions or diagrams printed on its casing by the manufacturer.
The weather conditions of the moment.
The fact that the user is on board a liferaft, a lifeboat or ship.
A definite standard process.
The turbocharger on a diesel engine is surging. Which one of the following options would be the most likely cause?
Dirty scavenging air cooler on the air side.
Dirty rotor blades and nozzle ring.
The lubrication oil pump is malfunctioning.
Worn out bearings on the turbocharger.
A 6-Volt DC relay is to be used with a 12-Volt power supply. The relay requires a current of 0,1 Amp. What is the series resistance required?
When the cable length exceeds approx. 10 meters we normally have to, in case of a Pt 100, in some way compensate for the cable resistance. Do we also have to do this if we choose to use a T802 temperature sensor?
Depends on temperature to be measured.
A medium speed diesel engine is used to drive a controllable pitch propeller through a suitable clutch and reduction gearbox. What should the propeller blade attitude normally be after the engine is started and before the clutch can be engaged?
The blades should be in the zero pitch position.
The blades should be in 20 % pitch position.
The blades should be in the full astern position.
The blades should be in the full ahead position.
The coil of a 12 V, 120 mA DC relay must be connected across a 24 V supply. What action should be taken?
Install a 100 Ohm resistor in parallel with the coil.
Install a 100 k Ohm resistor in parallel with the coil.
Install a 100 k Ohm resistor in series with the coil.
Install a 100 Ohm resistor in series with the coil.
A 6-Volt DC relay is to be used with a 12-Volt power supply. The relay requires a current of 0,1 Amp. What is the series resistance required?
When carrying out repair or maintenance tasks involving hot work a hot work permit must be issued. Select the correct option from those given which completes the following statement. The permit for hot work:
Should only cover specific hot work tasks, be valid for a specified time period and be issued by the person carrying out the work.
Should only cover specific hot work tasks and be valid for a specified time period.
Is valid for completion of the specific hot work tasks irrespective of the time taken.
The continuity resistance of a 100 m long × 25 sq. mm cable (rated at 100 A) is to be checked. Which of the following results would you anticipate?
Between 0,1 and 1,0 M Ohm.
Between 0,1 micro Ohm and 1,0 micro Ohm.
The muster list shall show the duties assigned to the different members of the crew. Which of the given duties necessarily have to be included in the muster list?
Preparation and launching of survival crafts.
Type of fires that can be encountered on board.
Preparation and starting of emergency generator.
What is the best way to avoid pollution from small oil-spills aboard a ship?
Contain any oil-spill onboard the ship.
Have dispersing chemicals ready for use in case of oil-spill.
Rig an oil boom around the ship.
Have sawdust ready for use.