The test consisted of 80 random questions. Total questions on this topic: 118
Your result: 95%
Right answers:
1
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.
2
Continuity testing of a delta connected three phase induction motor yields the following results: U-V = 3 Ohms, V-W = 3 Ohms, W-U = 6 Ohms. Which of the following is the likely condition?
Your answer is correct:
Open circuit winding between W and U.
3
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?
Your answer is correct:
Disconnect the thermocouple lead from the controller, and replace it with a mV source.
4
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, liquid or vapor, which will minimize creation of an electric arc as contacts open.
5
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:
Your answer is correct:
The sampling filter is partially blocked giving rise to wide pressure variations in the sampling chamber.
6
Continuity testing of a delta connected three phase induction motor yields the following results; U-V = 3 ohms, V-W = 3 ohms, W-U = 6 ohms. Which of the following is the likely condition?
Your answer is correct:
Open circuit winding between W and U.
7
In which of the following automated control processes will the time constant be of minor importance?
Your answer is correct:
Level control.
8
The main propulsion diesel engine is normally started by direct admission of compressed air. Which one of the following statements is correct?
Your answer is correct:
A heavily leaking starting air valve may cause an explosion in the starting air pipe system.
9
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.
10
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?
Your answer is correct:
Slightly superheated low pressure gas.
11
Some automated control systems use a master controller and a slave controller. What is the meaning of “remote mode” related to a slave controller?
Your answer is correct:
The slave controller receives the set-point from the output signal of the master controller.
12
Which is the preferred method for starting an air conditioning refrigeration compressor which has been shut down for a period of time?
Your answer is correct:
Start with suction valve throttled in to minimise risk of drawing liquid refrigerant into the compressor.
13
How can the pressure be regulated during start up of a positive displacement pump such as a gear pump?
Your answer is correct:
Adjustment of the pressure relief valve to recirculate part of the flow.
14
Why shall a duly qualified officer supervise any potential polluting operation?
Your answer is correct:
To avoid pollution.
15
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?
Your answer is correct:
22 Ohms.
16
Sometimes an early warning of failure in High Voltage switchboards may be an unpleasant smell. If the switchboard uses gas circuit breakers, which of the following may indicate a potential problem?
Your answer is correct:
Rotten eggs.
17
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?
Your answer is correct:
The heavy fuel is unstable leading to excessive high viscosity sludge formation.
18
In terms of automated control systems, what is typical for a continuous control system?
Your answer is correct:
It is possible to predict the control mathematically.
19
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?
Your answer is correct:
30 volts.
20
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:
Your answer is correct:
Fouling of the hull.
21
In what kind of measuring equipment might we find a Bourdon-tube?
Your answer is correct:
In a pressure transmitter.
22
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?
Your answer is correct:
Have the fuel pump phased and calibrated in a test workshop.
23
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?
What principle of measurement are viscosity controllers usually based on?
Your answer is correct:
Measurement of differential pressure.
25
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:
Your answer is correct:
Should only cover specific hot work tasks, be valid for a specified time period and be issued by the person carrying out the work.
26
Routine maintenance insulation testing of a three-phase induction motor should cover which measurements?
Your answer is correct:
U-E, V-E, W-E, U-V, V-W, W-U.
27
When performing electrical testing of a three phase motor, insulation resistance measurements may be influenced by which of the following?
Your answer is correct:
Temperature, humidity and surface contamination.
28
How can a lead-acid type battery be checked to confirm if it is fully charged or not?
Your answer is correct:
Measure the relative density (specific gravity) of the electrolyte.
29
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?
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.
30
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?
Your answer is correct:
One of the main switching elements in the triac has failed.
31
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.
Your answer is correct:
Set the proportional band to maximum width and the integral action to minimum (repeats per minute).
32
In case of pollution in US waters, do you always have to notify the National Response Center (OPA-90)?
Correct answer:
Yes, within thirty (30) minutes.
Your Answer:
No, not if the local US State Authority is correctly notified.
33
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?
Your answer is correct:
No.
34
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?
Your answer is correct:
Figure 1.
35
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 cylinder oil feed rate slightly and monitor the scavenge space drains.
36
What type of dynamic forces may cause indent in plating on forecastle deck and main deck in way of pillars inside forecastle?
Your answer is correct:
Pressure forces caused by green water on deck.
37
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?
Your answer is correct:
Electric motors will run at reduced speed, and will tend to overheat.
38
A 250 V contactor has been fitted to a 220 V supply. Which of the following symptoms might be observed?
Your answer is correct:
Contactor chattering (vibrating).
39
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.
40
A motor nameplate reads 75 hp. What is the reading in kW?
Your answer is correct:
56 kW.
41
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.
42
Low voltage ships tend to have insulated neutral systems. What is the reason for this?
Your answer is correct:
In the event of an earth fault vital equipment will not trip.
43
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?
Your answer is correct:
+/- 50 °C.
44
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.
45
Two reference points for pressure exist, absolute zero and atmospheric pressure. What are pressures measured relative to absolute zero called:
Your answer is correct:
Absolute pressure.
46
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?
Your answer is correct:
22 Ohms.
47
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 pitch position.
48
When turning a cascade control system, which of the following actions should be done first?
Correct answer:
Adjust the slave controller with the master controller in manual mode.
Your Answer:
Adjust the master controller with the slave controller disabled.
49
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?
Your answer is correct:
Slightly superheated low pressure gas.
50
An indicator card from a cylinder of a slow speed diesel engine shows a high maximum pressure occurring earlier in the cycle than normal with a normal compression pressure. From the options given, which action is most likely to identify the cause of the problem?
Your answer is correct:
Check if the fuel injection pump timing is correct.
51
A transformer overheats while taking a shore supply. Which is the likely cause?
Your answer is correct:
Incorrect frequency.
52
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?
Your answer is correct:
Fuel viscosity.
53
The majority of conventions adopted under the auspices of IMO fall into which of the three main categories?
Your answer is correct:
Maritime Safety, Prevention of Marine pollution, Liability and compensation.
54
Who is responsible for ensuring that your ship’s security plan meets the requirements of the ISPS Code?
Your answer is correct:
Company Security Officer.
55
What is the maximum current that a 15 Volt, 3 Watt Zenerdiode can handle without damage?
Your answer is correct:
0,2 A.
56
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?
Your answer is correct:
6 Ohms.
57
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.
Your answer is correct:
Reduced current and reduced torque.
58
What is the advantage of a transmitter with a narrow measurement range?
Your answer is correct:
Better linearity and increased accuracy.
59
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.
Your answer is correct:
I(2) = 4 A.
60
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?
Your answer is correct:
+/- 50 °C.
61
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?
Your answer is correct:
As soon as possible but not later than 2 weeks after he joins the ship.
62
A transformer overheats while taking a shore supply. Which is the likely cause?
Your answer is correct:
Incorrect frequency.
63
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?
Your answer is correct:
Stop bunkering, and establish facts, before bunkering is resumed.
64
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?
Your answer is correct:
60 Ohm.
65
The coil of a 12 V, 120 mA DC relay must be connected across a 24 V supply. What action should be taken?
Correct answer:
Install a 100 Ohm resistor in series with the coil.
Your Answer:
Install a 100 Ohm resistor in parallel with the coil.
66
When measuring viscosity with a restricted flow viscometer, the preferred sensing device is:
Your answer is correct:
Capillary tube.
67
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?
Your answer is correct:
Clearing escape routes.
68
Oil analysis results for a sample of diesel engine lubricating oil show a high level of tin. What could be the possible cause?
Your answer is correct:
Debris from damage to a white metal bearing.
69
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?
Your answer is correct:
ISM procedures in the ship’s safety manual.
70
A transformer overheats while taking a shore supply. Which is the likely cause?
Your answer is correct:
Incorrect frequency.
71
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?
Your answer is correct:
Reduce the time between overhauls due to increasing fouling.
72
Which personnel must undergo familiarization training on board?
Your answer is correct:
Everyone.
73
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?
Your answer is correct:
Replace the damaged chocks with resin based chocks of an appropriate size.
74
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?
Correct answer:
2,2 Ohms.
Your Answer:
22 Ohms.
75
Some fuel oil and lubricating oil separators have a facility to control the back pressure of the clean oil outlet during start up and operation. What is the purpose of this control function?
Your answer is correct:
To help to maintain the oil/water interface at the correct position.
76
What is the correct operation of the slow-turning facility fitted to some large 2-stroke main propulsion diesel engines?
Your answer is correct:
Slow turning should be set to operate automatically prior to engine start when engine has been stopped for 20 to 30 minutes during manoeuvring.
77
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?
Your answer is correct:
Flammable mixture is continuously present or present for long periods.
78
In case of a pollution in US waters, who shall notify the cleaning up contractor (OPA-90)?
Your answer is correct:
Qualified Individual.
79
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.
80
Which one of the listed requirements regarding abandon ship drills corresponds to present SOLAS regulation?
Your answer is correct:
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.