Тест по Engine department about Propulsion (CES v6.0)

Test results

The test consisted of 80 random questions.
Total questions on this topic: 84
Your result: 74%
Right answers:
1

In an automatic temperature control system, operating with a PID controller, which of the following settings or parameter adjustments may result in system oscillation?

Your answer is correct:

Gain too high.
2

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?

Your answer is correct:

2,2 Ohms.
3
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.

Your answer is correct:

V (2) = 50 V.
4

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?

Your answer is correct:

Engine speed control will be sluggish.
5

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?

Your answer is correct:

Crankcase relief valves/doors.
6

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?

Your answer is correct:

Sudden total loss of propulsive power may seriously endanger the vessel. This is a greater risk than engine damage.
7

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?

Correct answer:

2,2 Ohms.

Your Answer:

0,22 Ohms.
8
Which of the 4 alternatives shows a NPN bipolar transistor?

Your answer is correct:

Figure 3.
9

What is the bias value used for in a controller?

Correct answer:

It is used to remove steady state error at a reference set point.

Your Answer:

It is used to adjust a controller’s proportional response to error
10
In the diagram below we want to verify the resistance of the PT100 sensor fitted with compensation. What is the correct calculation?

Your answer is correct:

R(Pt100) = R1-R2.
11

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?

Your answer is correct:

Plus or minus 30 °C.
12

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?

Correct answer:

A reduced temperature difference between the seawater inlet and outlet and also between the lubricating oil inlet and outlet.

Your Answer:

A reduced temperature difference between the seawater inlet and outlet and an increase in the temperature difference between the lubricating oil inlet and outlet.
13

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?

Your answer is correct:

200 nm and capacity for evacuating more then 15 persons.
14

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?

Your answer is correct:

One or more cylinder air start valves are stuck open.
15

What does the term “stoichiometric mixture” mean when used in relation to combustion of hydrocarbon fuels?

Your answer is correct:

An ideal mixture of fuel and air in which all of the fuel and oxygen in the mixture are consumed during combustion.
16

Select, from the options given, the one most likely to result in a sudden reduction in main diesel engine operating speed during normal operation:

Correct answer:

Loss of signal to engine governor.

Your Answer:

Bad fuel oil quality.
17

Which ideal heat engine cycle is the vapour-compression refrigeration system based on?

Your answer is correct:

The reversed Carnot cycle.
18

The first step in completing an SSA is to:

Correct answer:

Create a list of potential motives for security incidents against your ship.

Your Answer:

Identify the key shipboard operations, systems, areas and personnel that are critical to protect.
19

What would the results of a TAN test, carried out on lubricating oil samples from a diesel engine, indicate?

Your answer is correct:

A measure of the of organic and inorganic acids in the lubricating oil.
20

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?

Your answer is correct:

The performance of the engine will be reduced noticeably.
21
The diagram shows a thyristor (SCR) with a Resistor and Capacitor (R and C). The RC network shown, performs which of the following applications?

Correct answer:

Divert fast voltage spikes which may lead to uncontrolled switch on.

Your Answer:

Provide voltage smoothing for SCR power supply.
22

A 3-phase cage rotor induction motor requires protection by a time delay overload trip. What is the reason for this?

Your answer is correct:

It will allow for inrush current or motor specific faults.
23

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?

Your answer is correct:

Increase the cylinder oil rate to neutralise the corrosive action of the combustion products or change to a more alkaline cylinder oil.
24

Master of every ship must provide:

Correct answer:

A link between the shipboard training officer and the company training officer ashore.

Your Answer:

Facilities to conduct training whenever required by the training officer.
25

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?

Your answer is correct:

Low flow or no flow in the cooling oil return line.
26

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?

Your answer is correct:

Some of the nozzle holes of the fuel injection valve are blocked.
27

Which of the following terms is used to describe a thermodynamic process in which no heat transfer into or out of the system occurs?

Your answer is correct:

Adiabatic.
28

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?

Your answer is correct:

Reduce the superheat setting on the instrument air refrigeration/dryer unit.
29

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?

Your answer is correct:

Poor quality fuel.
30

What would be a typical setting for the overspeed trip to operate and shut down the engine on a medium speed diesel engine?

Your answer is correct:

15 % above engine rated speed.
31

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?

Your answer is correct:

Percentage of available flow.
32

What is usually the effect on G when the ship is damaged with water ingress?

Correct answer:

It lowers.

Your Answer:

It first rises and then lowers.
33

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?

Your answer is correct:

Engine speed control will be sluggish.
34

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?

Your answer is correct:

16 mA.
35

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?

Your answer is correct:

The blades should be in the zero thrust position.
36

When selecting switchgear to work with High Voltage it is important to use an appropriate arcing medium. What is meant by arcing medium?

Your answer is correct:

The gas or vapour which will minimise creation of an electric arc as contacts open.
37

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?

Your answer is correct:

At least one hour.
38

When starting three phase induction motors which of the following starting methods will immediately apply rated voltage to the machine?

Your answer is correct:

Direct on Line.
39
What function is this circuit performing?

Correct answer:

Differentiating.

Your Answer:

Integrating.
40

Which one of the following items has to be included in an abandon ship drill according to SOLAS regulations?

Your answer is correct:

Checking that life-jackets are correctly donned.
41

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?

Your answer is correct:

Capillary tube in the viscometer is blocked giving high differential pressure at the DP cell.
42

A High Breaking Capacity fuse found in a Main High Voltage Switchboard will typically have fault level rating of?

Your answer is correct:

40 kA.
43

Which of the following is the minimum acceptable value of insulation resistance for High Voltage equipment?

Correct answer:

100 M Ohms.

Your Answer:

1 G Ohms.
44

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.

Correct answer:

Set the proportional band to minimum width and the integral action to maximum (repeats per minute).

Your Answer:

Set the proportional band to maximum width and the integral action to maximum (repeat per minute).
45

A High Breaking Capacity fuse found in a Main High Voltage Switchboard will typically have fault level rating of?

Your answer is correct:

40 kA.
46

The main propulsion diesel engine is normally started by direct admission of compressed air. Which one of the following statements is correct?

Correct answer:

A heavily leaking starting air valve may cause an explosion in the starting air pipe system.

Your Answer:

The starting air admission should continue until the engine has fired.
47

How often should the lifeboat wire falls be turned and renewed?

Your answer is correct:

Turned at intervals of not more than 30 months and renewed every 5 years.
48
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.

Correct answer:

Figure 3.

Your Answer:

Figure 1.
49

The turbocharger on a diesel engine is surging. Which one of the following options would be the most likely cause?

Your answer is correct:

Dirty scavenging air cooler on the air side.
50

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?

Your answer is correct:

Circumferential slip of the after clamp ring in the opposite direction to shaft rotation.
51

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.

Your answer is correct:

The governor droop settings are incorrectly set and are not matched.
52

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?

Your answer is correct:

The superheat control setting for the thermostatic expansion valve is set too low.
53

What type of dynamic forces may cause indent in plating on forecastle deck and main deck in way of pillars inside forecastle?

Correct answer:

Pressure forces caused by green water on deck.

Your Answer:

Forces created by waves on the forecastle.
54

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?

Your answer is correct:

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.
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?

Your answer is correct:

Sequential start initiated by pressure switches set at different switching pressures.
56

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:

Your answer is correct:

30 litters per nautical mile.
57

When considering instrumentation systems,what is the meaning of the expression “dead- band”?

Your answer is correct:

The controller will not react to a process change in this range.
58

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?

Your answer is correct:

Recondition the rod by surface grinding and build up using plasma spraying with metal similar to the original.
59
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?

Your answer is correct:

Figure 1.
60

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?

Your answer is correct:

The start is blocked because the air distributor has not moved to the astern position.
61

Onboard training should be organised in such a way that:

Your answer is correct:

It is an integral part of the overall training plan.
62

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?

Your answer is correct:

The filament is contaminated due to too high a concentration of hydrocarbons.
63

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?

Your answer is correct:

Set the proportional action first.
64

What is the normal slow down/shutdown temperature for the jacket cooling water outlet from a diesel engine cylinder?

Correct answer:

95-98 °C.

Your Answer:

85-88 °C.
65

In terms of automated control systems, what is typical for a continuous control system?

Correct answer:

It is possible to predict the control mathematically.

Your Answer:

The control valve will always be changing position.
66

Which of the below structures of bulk carriers are considered critical?

Your answer is correct:

Upper and lower connection of main side frames.
67

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?

Correct answer:

Refill the manometer with liquid with a higher density.

Your Answer:

Refill the manometer with liquid with a higher viscosity.
68

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?

Correct answer:

ISM procedures in the ship’s safety manual.

Your Answer:

Engine room log book.
69

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?

Your answer is correct:

The performance of the engine will be reduced noticeably.
70

Which of the following symptoms would indicate that the filter drier in a refrigeration circuit has become blocked?

Your answer is correct:

A large temperature drop across the drier.
71

What does the term “stoichiometric mixture” mean when used in relation to combustion of hydrocarbon fuels?

Correct answer:

An ideal mixture of fuel and air in which all of the fuel and oxygen in the mixture are consumed during combustion.

Your Answer:

An ideal mixture of fuel and air in which all of the fuel in the mixture is consumed during combustion with a minimum of excess air.
72

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?

Your answer is correct:

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.
73
Which electronic component or system is this graphical symbol illustrating:

Your answer is correct:

Bandpass filter.
74

Which of the following would be considered pollution, when discharged overboard, under the US water pollution laws?

Your answer is correct:

All of the mentioned.
75

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?

Correct answer:

The heavy fuel is unstable leading to excessive high viscosity sludge formation.

Your Answer:

The purifier bowl has not closed properly.
76

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?

Your answer is correct:

To stop the engine before any serious damage occurs due to excess inertial loads.
77

How is the prime mover load normally kept to a minimum when starting up an electric driven reciprocating type air compressor?

Your answer is correct:

By using an unloading device to keep the compressor suction valves open until the machine is up to speed.
78

Which statement about the use of profiling onboard a ship is true?

Correct answer:

A random selection process must be established.

Your Answer:

Detection equipment can be used in place of profiling.
79

What do you understand by the term Maximum Continuous Rating, MCR, of a diesel engine?

Your answer is correct:

The maximum load that the engine can operate at continuosly.
80

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?

Your answer is correct:

Increase the cylinder oil rate to neutralise the corrosive action of the combustion products or change to a more alkaline cylinder oil.