Тест по Engine department about Propulsion (CES v6.0)
Результаты прохождения теста
Тест состоял из 80 случайных вопросов.
Всего вопросов по данной теме: 84
Всего вопросов по данной теме: 84
Ваш результат: 90%
Правильные ответы:
1
The temperature control for the central cooling system low temperature circuit has failed and a new 3 term controller is to be fitted. Which of the given options would be the correct method of setting up the controller?
Ваш ответ правильный:
Set the proportional action first.2
What does the term “stoichiometric mixture” mean when used in relation to combustion of hydrocarbon fuels?
Ваш ответ правильный:
An ideal mixture of fuel and air in which all of the fuel and oxygen in the mixture are consumed during combustion.3
The turbocharger on a diesel engine is surging. Which one of the following options would be the most likely cause?
Ваш ответ правильный:
Dirty scavenging air cooler on the air side.4
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.
Правильный ответ:
Set the proportional band to minimum width and the integral action to maximum (repeats per minute).Ваш ответ:
Set the proportional band to maximum width and the integral action to maximum (repeat per minute).5
Which of the following would be considered pollution, when discharged overboard, under the US water pollution laws?
Ваш ответ правильный:
All of the mentioned.6
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?
Ваш ответ правильный:
The blades should be in the zero thrust position.7
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?
Ваш ответ правильный:
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.8
What would be a typical setting for the overspeed trip to operate and shut down the engine on a medium speed diesel engine?
Ваш ответ правильный:
15 % above engine rated speed.9
When starting three phase induction motors which of the following starting methods will immediately apply rated voltage to the machine?
Ваш ответ правильный:
Direct on Line.10
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?
Ваш ответ правильный:
Preparation and launching of survival crafts.11
A 3-phase cage rotor induction motor requires protection by a time delay overload trip. What is the reason for this?
Ваш ответ правильный:
It will allow for inrush current or motor specific faults.12
A U tube manometer is used to measure the pressure delivered by a ventilation fan. Following replacement of the fan by a larger unit with a higher delivery rate and pressure the liquid is blown out of the open end of the manometer. Which of the options given will allow the manometer to be used to measure the delivery pressure of the larger fan?
Ваш ответ правильный:
Refill the manometer with liquid with a higher density.13
A High Breaking Capacity fuse found in a Main High Voltage Switchboard will typically have fault level rating of?
Ваш ответ правильный:
40 kA.14
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?
Ваш ответ правильный:
Increase the cylinder oil rate to neutralise the corrosive action of the combustion products or change to a more alkaline cylinder oil.15
Which of the following symptoms would indicate that the filter drier in a refrigeration circuit has become blocked?
Ваш ответ правильный:
A large temperature drop across the drier.16
Which of the below structures of bulk carriers are considered critical?
Ваш ответ правильный:
Upper and lower connection of main side frames.17
What is the bias value used for in a controller?
Ваш ответ правильный:
It is used to remove steady state error at a reference set point.18
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?
Ваш ответ правильный:
One or more cylinder air start valves are stuck open.19
A low exhaust temperature in one cylinder of a diesel engine is noticed during routine checks. Which of the options given is the most likely cause of this?
Ваш ответ правильный:
Some of the nozzle holes of the fuel injection valve are blocked.20
Which one of the following items has to be included in an abandon ship drill according to SOLAS regulations?
Ваш ответ правильный:
Checking that life-jackets are correctly donned.21
The range of a transducer is 0-200 bar and the output signal is 4-20 mA. What is the output signal when the process value is 100 bar?
Ваш ответ правильный:
16 mA.22
A transformer overheats while taking a shore supply. Which is the likely cause?
Ваш ответ правильный:
Incorrect frequency.23
A heat exchanger of the tube and shell type is used for cooling lubricating oil with seawater as the secondary fluid. Which of the options would indicate that the tube stack was becoming fouled (scaled or coked) rather than blocked?
Ваш ответ правильный:
A reduced temperature difference between the seawater inlet and outlet and also between the lubricating oil inlet and outlet.24
Which of the 4 alternatives shows a NPN bipolar transistor?
Правильный ответ:
Figure 3.Ваш ответ:
Figure 4.25
In the event of a diesel engine crankcase explosion which of the safety devices fitted to the engine is designed to minimise the risk of a secondary explosion?
Ваш ответ правильный:
Crankcase relief valves/doors.26
The operation of a diesel engine is controlled by a mechanical-hydraulic, compensated speed sensing governor. How will the governor control be affected if the compensation needle valve is closed in and the engine load changes?
Ваш ответ правильный:
Engine speed control will be sluggish.27
A viscosity controller for the main diesel engine fuel oil supply is giving poor control resulting in the viscosity of the fuel oil being too low at the engine. Which of the defects given in the options is likely to be the cause of this problem?
Ваш ответ правильный:
Capillary tube in the viscometer is blocked giving high differential pressure at the DP cell.28
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?
Ваш ответ правильный:
The performance of the engine will be reduced noticeably.29
Prior to removing the access doors to a pressure vessel for internal maintenance it should be ensured that all pressure has been relieved. As well as a zero indication on a pressure gauge which other measure, from the options given should be taken to confirm this prior to commencing the work?
Ваш ответ правильный:
Open the drain valve while pressure still shows on the gauge and to check it is clear. Outflow should cease as the pressure gauge reaches zero.30
Select, from the options given, the one most likely to result in a sudden reduction in main diesel engine operating speed during normal operation:
Правильный ответ:
Loss of signal to engine governor.Ваш ответ:
Bad fuel oil quality.31
Many large, slow speed diesel engines have direct oil cooling of the piston crowns provided. An automatic slow down and alarm are sometimes fitted to protect against failure of this system. Which parameter is usually used to initiate this slow down?
Ваш ответ правильный:
Low flow or no flow in the cooling oil return line.32
Maintenance is to be carried out on a diesel engine. How long after stopping the engine should the cooling water and lubricating oil be kept circulating in order to avoid any undue thermal stress from residual heat?
Ваш ответ правильный:
At least one hour.33
Some vessels have a central hydraulic system consisting of a number of hydraulic power packs for driving cargo pumps, deck machinery, ship’s cranes, etc. Which parameter is normally used to automatically bring the power packs on and off line to match operational demand?
Правильный ответ:
Percentage of available flow.Ваш ответ:
Percentage of maximum pressure being used.34
A transformer, rated at 22 kVA, 440/220 Volts, 60 Hz, is used to step down the voltage for 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?
Правильный ответ:
2,2 Ohms.Ваш ответ:
22 Ohms.35
The diagram shows a thyristor (SCR) with a Resistor and Capacitor (R and C). The RC network shown, performs which of the following applications?
Ваш ответ правильный:
Divert fast voltage spikes which may lead to uncontrolled switch on.36
In a PID controller it is possible to change the setting of the Proportional band (P), the Reset time (I) and the Rate time (D). Please indicate which curve shows the typical response to a step change in input, if the setting of the reset time is too small.
Ваш ответ правильный:
Figure 3.37
Master of every ship must provide:
Ваш ответ правильный:
A link between the shipboard training officer and the company training officer ashore.38
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?
Ваш ответ правильный:
The performance of the engine will be reduced noticeably.39
What is the normal slow down/shutdown temperature for the jacket cooling water outlet from a diesel engine cylinder?
Ваш ответ правильный:
95-98 °C.40
Which ideal heat engine cycle is the vapour-compression refrigeration system based on?
Ваш ответ правильный:
The reversed Carnot cycle.41
For a ship operating or calling in US waters, COTP can request (OPA-90)?
Ваш ответ правильный:
Unannounced drills at any time.42
How long after starting a refrigeration compressor should the oil separator return valve be opened?
Ваш ответ правильный:
It should be opened once the oil separator unit has warmed up.43
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?
Ваш ответ правильный:
Circumferential slip of the after clamp ring in the opposite direction to shaft rotation.44
The main propulsion diesel engine is normally started by direct admission of compressed air. Which one of the following statements is correct?
Ваш ответ правильный:
A heavily leaking starting air valve may cause an explosion in the starting air pipe system.45
Part of the outer surface of a refrigeration compressor crankcase and the refrigerant return line near the compressor ice up heavily during normal operation. Which of the options given is the most likely cause of this problem?
Ваш ответ правильный:
The superheat control setting for the thermostatic expansion valve is set too low.46
A transformer is 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?
Ваш ответ правильный:
2,2 Ohms.47
After a couple of hours of operation the failure alarm sounds for a heavy 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?
Ваш ответ правильный:
The heavy fuel is unstable leading to excessive high viscosity sludge formation.48
Medium and high speed diesel engines used for electrical generation duties on board ship have overspeed protection devices fitted to protect the engine in case the electrical generator trips while carrying high loads. Why are these devices necessary?
Ваш ответ правильный:
To stop the engine before any serious damage occurs due to excess inertial loads.49
Two identical medium speed engines are connected through clutches and a reduction gearbox to a single controllable pitch propeller. It is noted during normal operation that the load sharing between the engines is uneven with one engine taking a greater proportion of the load as the total load increases even though they are equally loaded at low load. Select from the options given the most likely cause of this problem.
Ваш ответ правильный:
The governor droop settings are incorrectly set and are not matched.50
Which of the following terms is used to describe a thermodynamic process in which no heat transfer into or out of the system occurs?
Ваш ответ правильный:
Adiabatic.51
Which of the following is the minimum acceptable value of insulation resistance for High Voltage equipment?
Ваш ответ правильный:
100 M Ohms.52
What does the term “stoichiometric mixture” mean when used in relation to combustion of hydrocarbon fuels?
Ваш ответ правильный:
An ideal mixture of fuel and air in which all of the fuel and oxygen in the mixture are consumed during combustion.53
A High Breaking Capacity fuse found in a Main High Voltage Switchboard will typically have fault level rating of?
Ваш ответ правильный:
40 kA.54
New MARPOL regulations came into effect from July 93 stating that the previous instantaneous rate of discharge of oil content (60 litters per nautical mile) was changed to:
Ваш ответ правильный:
30 litters per nautical mile.55
A compressed air supply system has two automatically controlled air compressors. When demand is high both compressors are needed to meet the delivery requirements. What is the best method for controlling the compressors to meet a varying, but intermittent demand?
Ваш ответ правильный:
Sequential start initiated by pressure switches set at different switching pressures.56
This circuit shows a transformer with two windings, N (1) = 2 000 and N (2) = 1 000 turns, on a common magnetic circuit. Assume that there are no energy losses in the transformer itself. Calculate the output voltage V (2) when the input voltage is V (1) = 100 Volt.
Ваш ответ правильный:
V (2) = 50 V.57
Marine diesel engines are normally provided with automatic protection devices which operate in the event of abnormal conditions arising. Why would medium speed engines used for main propulsion normally only automatically slow down for certain abnormal conditions but automatically shut down for the same conditions when used to drive an alternator?
Ваш ответ правильный:
Sudden total loss of propulsive power may seriously endanger the vessel. This is a greater risk than engine damage.58
HEL-H is the abbreviation of a heavy helicopter radius of action for rescue purposes. What do you think the radius and evacuating capacity of the helicopter is?
Ваш ответ правильный:
200 nm and capacity for evacuating more then 15 persons.59
In an automatic temperature control system, operating with a PID controller, which of the following settings or parameter adjustments may result in system oscillation?
Ваш ответ правильный:
Gain too high.60
A combustible gas indicator of the catalytic filament type is used to check the atmosphere in an enclosed space onboard ship. When taking readings in a fuel tank which has been emptied for cleaning the meter reading initially rises and then falls back to zero. What is the likely defect, if any, in the instrument when this type of behaviour is displayed?
Ваш ответ правильный:
The filament is contaminated due to too high a concentration of hydrocarbons.61
The instrument air system is suffering from excess water carry over to the instrument air lines. The air intake to the compressor has very high humidity. Which of the actions given in the options will most likely result in reducing this problem?
Ваш ответ правильный:
Reduce the superheat setting on the instrument air refrigeration/dryer unit.62
What function is this circuit performing?
Ваш ответ правильный:
Differentiating.63
Which electronic component or system is this graphical symbol illustrating:
Ваш ответ правильный:
Bandpass filter.64
In terms of automated control systems, what is typical for a continuous control system?
Ваш ответ правильный:
It is possible to predict the control mathematically.65
Onboard training should be organised in such a way that:
Ваш ответ правильный:
It is an integral part of the overall training plan.66
When considering instrumentation systems,what is the meaning of the expression “dead- band”?
Ваш ответ правильный:
The controller will not react to a process change in this range.67
What type of dynamic forces may cause indent in plating on forecastle deck and main deck in way of pillars inside forecastle?
Ваш ответ правильный:
Pressure forces caused by green water on deck.68
What would the results of a TAN test, carried out on lubricating oil samples from a diesel engine, indicate?
Правильный ответ:
A measure of the of organic and inorganic acids in the lubricating oil.Ваш ответ:
A measure of the organic acids in the lubricating oil.69
When selecting switchgear to work with High Voltage it is important to use an appropriate arcing medium. What is meant by arcing medium?
Ваш ответ правильный:
The gas or vapour which will minimise creation of an electric arc as contacts open.70
A medium speed diesel engine, operating with a pulse turbocharging system, has been adjusted to have good power balance. What would the cylinder exhaust gas temperatures, relative to each other, be expected to be?
Ваш ответ правильный:
Plus or minus 30 °C.71
When trying to reverse a large slow speed diesel engine in the astern direction it cannot be turned on air even though it will start in the ahead direction. What is the likely cause of this problem?
Правильный ответ:
The start is blocked because the air distributor has not moved to the astern position.Ваш ответ:
The reversing servo for the fuel pumps has stuck in the ahead position.72
This circuit consists of a voltage source V, a change-over switch S, a resistor R and a capacitor C. The voltage/time figures 1 to 4 show changes in the voltage V(C) when the switch S is suddenly shifted from position 1 to 2 at time t = 0. Only one of the diagrams is correct. Which?
Ваш ответ правильный:
Figure 1.73
Which of the following options is the most likely to result in the maximum cylinder pressure for all cylinders on a diesel engine to be lower than normal?
Ваш ответ правильный:
Poor quality fuel.74
How is the prime mover load normally kept to a minimum when starting up an electric driven reciprocating type air compressor?
Ваш ответ правильный:
By using an unloading device to keep the compressor suction valves open until the machine is up to speed.75
What do you understand by the term Maximum Continuous Rating, MCR, of a diesel engine?
Ваш ответ правильный:
The maximum load that the engine can operate at continuosly.76
The piston rod of a large two stroke diesel engine has been damaged and is heavily scored in way of the piston rod gland (stuffing box). It has been decided that it is economically viable to recondition the rod at a shoreside facility. Select, from the options given, the most suitable repair method that should be used?
Ваш ответ правильный:
Recondition the rod by surface grinding and build up using plasma spraying with metal similar to the original.77
During maintenance work on the main engine a problem arises regarding the lifting of a main component in that the manufacturer’s instructions ado not apply to the engine as fitted and present a hazard. In which of the information/record sources given in the options, is it most important to record the information relating to this anomaly?
Ваш ответ правильный:
ISM procedures in the ship’s safety manual.78
During inspection and calibration of a cylinder unit, the liner is found to be worn in a cloverleaf pattern with maximum wear midway between the lubrication points. What action is necessary to rectify the problem?
Ваш ответ правильный:
Increase the cylinder oil rate to neutralise the corrosive action of the combustion products or change to a more alkaline cylinder oil.79
How often should the lifeboat wire falls be turned and renewed?
Ваш ответ правильный:
Turned at intervals of not more than 30 months and renewed every 5 years.80