Тест складається із 80 випадкових питань.
Усього питань на цю тему: 118
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.
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.
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.
A thermistor, which provides feedback for a thermal control system, is suspected to have failed. Assuming there is no available replacement, which of the following methods may be used to prove it has failed?
Disconnect the thermocouple lead from the controller, and replace it with a mA source.
Connect a mA source in parallel with the thermocouple connections.
Connect a mV source in parallel with the thermocouple connections.
Disconnect the thermocouple lead from the controller, and replace it with a mV source.
The temperature control for a hot water system is very erratic with the temperature gradually rising and then suddenly falling and vice versa even though system demand is fairly constant. Which of the options given is the most likely cause of this problem?
Control valve gland is over tightened.
Controller integral action reset time is too fast.
Control valve actuator diaphragm is ruptured.
Control air pressure supply is too low.
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 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?
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?
Slightly superheated low pressure gas.
Wet vapour at high pressure.
Sub-cooled liquid at low pressure.
Cold liquid at high pressure.
In the context of an automated process control system, what is understood by the expression Master Controller?
The primary controller in a cascade control system.
The captain’s controller.
State of the art controller.
The best possible control system.
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.
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.
What is the advantage of a transmitter with a narrow measurement range?
Do not need any calibration.
Better linearity and increased accuracy.
The charge air pressure supplied to a diesel engine, which is normally 2,0 bar, is reduced to 1,5 bar. What will be the likely effect on the engine operation?
The performance of the engine will be reduced noticeably.
The performance of the engine will be similar to normal conditions.
The turbochargers cooling water flow will increase.
The cylinder cooling water flow will increase.
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.
The majority of conventions adopted under the auspices of IMO fall into which of the three main categories?
Maritime Safety, Prevention of Marine pollution, Liability and compensation.
Maritime Safety, STCW, Maritime Security.
There are no conventions that fall under IMO.
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.
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?
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.
Some diesel engines have alarm and slow down protection in the event of a fire in the scavenge boxes. Choose the option which would be a typical set point for giving a slow down of the engine in the event of a scavenge box fire?
How often should the lifeboat wire falls be turned and renewed?
Turned at intervals of not more than 30 months and renewed every 5 years.
Renewed every three years.
Turned every 30 months and needs only to be renewed if the wire is in poor condition.
Turned every 2 years and renewed every 4 years.
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.
When turning a cascade control system, which of the following actions should be done first?
Adjust the slave controller with the master controller in manual mode.
Adjust both controllers at the same time.
Adjust the slave controller with the master controller in auto mode.
Adjust the master controller with the slave controller disabled.
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?
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.
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 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.
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?
In case of pollution in US waters, do you always have to notify the National Response Center (OPA-90)?
Yes, within thirty (30) minutes.
Yes, within three (3) days.
No, not if the local US State Authority is correctly notified.
No, only the shipowner can notify NRC.
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).
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.
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.
A transformer overheats while taking a shore supply. Which is the likely cause?
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?
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.
The main propulsion diesel engine is normally started by direct admission of compressed air. Which one of the following statements is correct?
A heavily leaking starting air valve may cause an explosion in the starting air pipe system.
The starting air admission should continue until the engine has fired.
If the engine does not turn when the starting air is applied the turning gear can be used together with starting air to start the engine.
If the starting air pressure is too low a pressurized oxygen bottle from the welding equipment can be used for an emergency start of the engine.
What should be the healthy continuity resistance of a 220V, 2,2kW, 10A heating element, when checked near to it’s rated operating temperature?
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?
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 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 should a crew member joining a ship for the first time be given some training and instructions in the use of the ship’s fire-fighting appliances?
As soon as possible but not later than 2 weeks after he joins the ship.
As soon as possible but not later than 2 days after he joins the ship.
As soon as possible but not later than 24 hours after he joins the ship.
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.
Which personnel must undergo familiarization training on board?
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.
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.
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.
When measuring viscosity with a restricted flow viscometer, the preferred sensing device is:
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?
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.
How can the pressure be regulated during start up of a positive displacement pump such as a gear pump?
Adjustment of the pressure relief valve to recirculate part of the flow.
Positive displacement pumps operate at constant pressure and cannot be regulated.
By throttling the discharge valve.
By throttling the suction valve.
The fuel tank contents gauges onboard a vessel are of the air bubble and bell type. The gauges are calibrated for a different fuel type to the actual fuel in the tanks. When correcting the actual contents of the tanks from the gauge readings which of the parameters given in the options is the most important?
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.
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.
In tanker operations, there will be some areas and zones where flammable or explosive vapour, gas, or dust may be expected. Such areas are classified as hazardous. What is meant by hazardous area Zone 1?
Flammable mixture is continuously present or present for long periods.
Flammable mixture is not continuously present, but will be present during normal operations.
Flammable mixture is not present at all times.
Flammable mixture would not normally be present or it would be present for a short period only.
A transformer overheats while taking a shore supply. Which is the likely cause?
Why shall a duly qualified officer supervise any potential polluting operation?
To inform the authorities.
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.
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).
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.
What principle of measurement are viscosity controllers usually based on?
Measurement of differential pressure.
Measurement of two different temperatures.
Measurement of temperature.
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.
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 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.
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.
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.
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?
Apply reduced voltage to the element for a few minutes. Then retest and if ok put into service.
Put the element into service.
Wash the element in a degreasing agent. Then retest and if ok put in into service.
You are in charge of a night bunkering operation. The delivery rate from the supplier is high and you are filling six tanks simultaneously. You lose track of the progress of the operation and feel that you are losing control of the situation. What action should you take?
Stop bunkering, and establish facts, before bunkering is resumed.
Open more tanks to slow down the filling rate of individual tanks.
Prepare yourself and the crew for an overflow.
Request a reduction in the delivery rate to try and gain some time.
When considering instrumentation systems, what is the meaning of the expression “dead-band”?
The controller will not react to a process change in this range.
It will take some time before the controller will react to a change.
The controller will enter “sleep mode”.
The controller will not respond to adjustment of set-point.
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.
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 ship’s electrical system operates at 60 Hz, but when connected to shore supply it is supplied with 50 Hz. Which of the following would you expect?
Electric motors will run at reduced speed, and will tend to overheat.
Earth faults are more likely.
Electric motors will run at increased speed and will tend to overheat.
Generators are more sensitive to reverse power faults.
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.
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?
Some ships generate electrical power at 440 V, 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?
The overall ship’s electrical load does not justify a 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.
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 a High Voltage generating plant at the time of manufacture, so they used what was available at the time.
Why is it necessary to have an effective ballast water management plan which includes provision for changing out ballast in open water rather than discharging ballast in coastal waters?
To avoid the introduction of non-indigenous species of marine life from one area to another.
To keep the ballast water fresh in the ballast tanks during long voyages.
To allow ballast tank inspections to be carried out during ballast passage.
To ensure that ballast tanks are always pressed up during a ballast voyage to avoid free surface effects.
A transformer overheats while taking a shore supply. Which is the likely cause?
What is the purpose of the relief valves fitted to the doors and casing of 2-stroke diesel engine crankcases?
To relieve excess pressure in the crankcase resulting from a crankcase explosion.
To relieve excess pressure in the crankcase resulting from piston rod gland leakage.
To maintain a constant pressure in the crankcase.
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?
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.