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Worksheetsengineer
Total questions: 217
Worksheet time: 2hrs 49mins
1. What form of power loss is the result of resistance in a distribution circuit in heating of conductors?
•Line loss
•R drop
•Line droop
•hysteresis
2. External shunt are sometimes provided in ammeters to _______.
•prevent damage from heat generated by the shunt
•increase meter sensitivity
•permit shunts with larger resistance to be utilized
•enable the construction of meter with virtually unlimited range
3. What is the ratio between the insulation resistance (IR) value measured after the application of the test voltage continuesely for 10 minutes to the IR valued measured after 1 minute of application?
•Polarization Index or PI value
•Power Loss or I2R value
•Insulation Resistance or IR value
•Grounding Index or GI
4. What safety device prevents the opening of the remote main starting non-return valve if the engine turning gear is engaged?
•Sequence valve
•Interlock
•Proximity switch
•Puncture valve
5. A medium pressure water tube boiler uses a level differential pressure transmitter to detect the actual level inside the drum. What signal are applied to the the transmitter in order to detect the process parameter?
•Main steam drum and floe pressure
•Pressure from the HP and LP side of the steam drum
•Pressure from the steam side of the boiler
•Pressure from the water side of the boiler
A mili-ammeter with a full scale deflection reading of 100 milliamps, is known to have an accuracy of (+/-)2%. A meter reading of 10 milliamps would indicate a line current of between_______
9.8 to 10.0 milliamps
8.0 to 10 milliamps
0.8 to 110.2 milliamps
8.0 to 12 milliamps
What is the most inefficient method of the voltage reduction from the stand point of the power loss
•Capacitor and inductor in series with the load
•Capacitor in series with the load
•Resistor in series with the load
•Induction in series with the load
What can be obtained in an opened circuit if we use the instrument called megger tester?
•Insulation efficiency.
•Maximum load
•Resistance of wire
•Current flaw
On a main switchboard, if all three ground detection lamps remain litted at the half intensity when the button is depressed, which of the listed condition will be indicated?
•All three phases are grounded
•The test switch is grounded
•The current transformer are shorted
•No earth fault exist
In HV system IR measurement, what should be the range of the megger tester to be used for up to 6.6kV?
•10,000 VDC megger
•1,000 VAC megger
•1,000 VDC megger
•5,000 VDC megger
Which of the following indicate the temperature in Ac generator?
•Pyrometer
•Deep well thermometer
•Imbedded thermocouples
•Standard thermometers
The main engine reversing mechanism is tested by repeated changes from ahead to astern vice-versa after each change, the engine is started. What does this test provided?
•Information concerning the minimum starting air pressure at which reversing and starting can be accomplished
•Information on how much reduction of starting air pressure at every start
•Information on the durability of the main starting valves after successive starts
•Information on how fast the main air compressors can fill the air bottles after every start
Pneumatic directional valve symbols consist of either letters or the numbers 1,2,3,4 and 5 as per DIN ISO 5599. What does number 1 represents?
•Exhaust line
•Air source connection
•Working line
•Control line
Which of the following statements represent the FIRST step in seating new brushes on slip rings?
•apply seating compound under the brushes and run at no load for 2 hours
•apply seating compound around the slip rings and slide it back and forth between the brushes and the slip ring
Which of the following statements represent the FIRST step in seating brushes on slip ring?
•press the brushes against the slip ring with a wood block
Before an insulation test is carried out inside the group starter panel circuit board, the wirings leading to the sensitive circuits shall be?
•grounded
•taken away
•removed
•tested first
What will be the phase angle of six-pole, three-phase, rotating field generator?
•180⁰
•360⁰
•60⁰
•120⁰
In a diesel engine, once the pilot air control valve is moved by the lever to either ahead or astern, it admits air________.
•simultaneously to the remote starting air valve and air distributor
•to the starting distributor first
•simultaneously to the cylinder starting valve and remote starting air valve
•to the remote starting air valve first
In which of the following mode does a (JFET) operates?
•Depletion
•Expansion
•Contraction
•Shirking
Some of the advantages of HV system on the ships include usage of high-class insulation on conductors (generally ‘F’ class and above) and special switch gears required to prevent arcing. What is another disadvantages?
•Difficulty in installation and higher cost
Copper loss are increased when compared to LV system, as the current flow is more.
•Higher voltages have greater risk and hence require stringent safety procedures.
•Using HV electric propulsion further increases engine room size, hence, lesser cargo space.
. Manual/standby indicator red lamp is lighted depending on the position of the interlock auto-change selector switch. When the lamp is lighted it indicates that the starter operation mode is in?
out of the service mode
•standby mode
•running mode without load
•in service mode
In paralleling two generators, what does it means when the synchronizing lamps remain lighted as the synchroscope pointer approaches the zero degree position.
•Two generators are in phase
The voltage reading of incoming generator is lower than 440V
•Two are in parallel connection
•The flow of power is in reverse direction
Current used primarily because it can be transmitted inexpensively and because it can be used for application for which the current is not suitable?
Direct current
Electric charge
Electricity
•Alternating current
The automatic combustion control system for some auxilliary boiler are designed to cycle burner on in response to ______.
low steam pressure
fuel return pressure
•furnace air pressure
low fuel pressure
A forward-biased diode acts like a switch that is _______.
open
relay
closed
capacitor
The differential pressure signal, either electrically or pneumatically, corresponds to the water level in the boiler, 0% level corresponds to 4 mA 100 % level corresponds to 20 mA. What should be the corresponding mA signal applied for a 50% water level on a well calibrated transmitter?
10 mA
6 mA
18 mA
12 mA
On a vessel with turbo-electric drive, which of the following conditions would be indicate that the propulsion motor had dropped out of synchronization with the propulsion generator?
•Closed contact in the filed circuits
•Excessive vibration of the vessel
•Tripped main motor interlock
•Overheated crosstie busses
The most common source of excitation for synchronous motors in a/an _______.
•motor attenuator set
•DC exciter generator
•low voltage battery
•AC supply
If the relay coil is not “open” when all indicates that it should be energized with rated voltage measured across the coil is present, probably the cause would be?
•Coil is open
•Fuse is blown
•Transformer is defective
•Auxiliary contact with coil is defective
An operating characteristic on the name plates of shipboard AC motor is .
•locked rotor locked
•rated slip
•temperature rise
•the type of winding
What type of motor often found on machines that have friction-type loads, such as conveyors, gear-type pumps, and load lifting equipment wherein the horsepower required increases when the speed increases?
•Constant HP/Variable torque
•Constant HP/Constant torque
•Variable torque/Variable HP
•Constant torque/Variable HP
In addition to short circuits and sustained overloads, fuses are likely to blow due to ______
•all of these choice
low ambient temperature
low resistance
•loose fuse clips
On some diesel electric ships, the DC propulsion motor will only half speed when the generator fields are fully exited. Speeds above this are obtained by_____.
raising the generator engine speed
•rotating brush alignment
lowering the generator engine speed
•decreasing excitation
Silicon diodes designed for a specific breakdown voltage, become useful as an electronic power supply voltage regulation, is called __________.
hot-carrier diodes
•Zener-diodes
•tunnel diodes
•compensating diodes
Which of the following is the Japanese International Standard (JIS) markings in electrical equipment and is recognized by the Japanese class society?
•NK
•Nippon Go
Nippon Koyo
•Nippon Kusen
Why is copper loss and iron less high voltage system?
•Because the current draw with HV is much less
•Because the conductor’s cross-sectional area is reduced in HV installation
•Because the copper and iron are the best conductors for HV installation
•Because the current carrying capacity of conductor increase in HV installation
In an electro-hydraulic steering gear system, whenwill the variable displacement pump be placed on stroke?
When the six-way valve is opened
•When the ram relief valve lift
•When the helm is at any angle other than amidships
•When the rudder angle is different from the position of the helm
Negative ions going to the Positive electrode is called ________.
•electron
•anions
•cations
•proton
In the generator synchronizing board, circuit breaker’s closing operation of an incoming generator is done when synchronizing lamp indicator is at the ?
Top part of the cycle
•No indication
•Bottom part of the cycle
•90? Before reaching the top cycle
The simplest method of controlling the terminal voltage of compound-wound DC generator is with a _____.
•balance coil diverting neutral current through the shunt field
•hand-operated field rheostat connected in series with the shunt field circuit
•carbon pile regulator in series with the load
•separate exciter with the ssssshunt field
Which of the following statement is correct concerning electrical wirings?
•Electric cable covering should never be grounded
•When passing through the bulkheads, they should be fitted with the watertight stuffing.
•Electrical cables must be rigidly held in place by armuored cable, or glued in the place with non-metallic insulation.
•Electrical cables should be grounded in the bulkheads.
Which battery charging circuits is used to maintain a wet-cell, lead-acid and storage battery?
•Power charging station
•Trickle charging circuit
Bulk charging unit
•Inverter
Which among the below systems on board applies an open-loop control system?
•System for remote opening and closing the engine room dampers
•Auxilliary engine RPM control
•Steering gear system
•Boiler water level control system
In a diesel starting air system, from the air receiver, where is the compressed air for starting supplied first before the cylinder air starting valve?
•Ahead or astern directional valve
•Starting solenoid valve
•Automatic main starting valve
•Starting air distributor
What instrument is used in order to adjust the combustion air:fuel ratio of the boiler accordingly?
•CO analyzer
•Smoke density sensor
•Ringleman scale
•Flue gas analyzer
Regarding an AC generator connected to the main electrical bus; as the electric load and power factor vary, a corresponding change is reflected in the generator armature reaction. These changes in armature reaction are compensated for by the _______.
voltage regulator
•balance coil
phase-balance relay
•governor speed droop setting
What is the function of the main engine running interlock?
•It prevents the engine from starting in reverse direction until all the cam roller of exhaust valve have shifted.
•It prevent the engine from starting direction until all air distributor valve have shifted.
•It prevents the engine from starting in reverse direction until it is in a complete stop.
•It prevents the engine from starting in reverse direction until all cam of fuel pump have shifted.
On a vessel with turbo-electric drive, which of the following conditions would indicate that the propulsion motor had dropped out of synchronization with the propulsion generator?
•Tripped main motor interlocks
•Overheated crosstie busses
•Excessive vibration of the vessel
•Closed contact in the field circuits
A controller with floating action has a controlled variable where the range of values produces no motion of the final control element. What do you call this range of values?
•Neutral zone
Set point
•Offset
•Control point
In a boiler on auto-operation, the panel will send a signal to the starter of FD fan to operate and initiate a pre-purging operation for about 3 to 4 minutes as set by timer switch. During this purging sequence, what is the position of the FD fan air suction damper?
•25% open
•50% open
•100% open
•100% close
What kind of electrical wiring configuration of a three-phase motor in which one end of each of the three phases in connected to the other phase internally, and the remaining end of each phase is then brought out externally and connected to the power line?
•Wye configuration
•Dual voltage configuration
•Forward-reverse configuration
•Delta configuration
. Each hydraulic system must be fitted with a pressure relief valve downstream of the pump of prevent accident and damaged cause by excessive pressures. Spring loaded relief valve are used to adjust the working pressures and limit the operating pressures or are also emplyoded as safety valves. What kind of relief valves are used whenever of hydraulic oils are involved?
•Counter-balance valves
•One-way flow control relief valves
•Pilot controlled pressure relief valves
•Solenoid controlled pressure relief valves
The shunt used in an ammeter should be connected in .
Series with the load and in parallel with the meter movement
Parallel with the load an in parallel with the meter movement
Parallel with the load and in series with the meter movement
Series with the load and in series with the meter movement
Most AC voltmeters are calibrated to read _______.
•Peak voltage
Peak-to-peak voltage
Root-mean-square voltage
•Average voltage
In a standard motor starter panel, a motor is started by pressing the start push button switch. This energizes a starting relay an a ?
transformer
starter relay
thermal relay
contactor
Which of the listed battery charging circuits is used to maintain a wet cell, lead-acid, storage battery in a fully charged state during long period of disuse ?
•Trickle charging circuit
•Quick charging circuit
•Normal charging circuit
•High ampere charging circuit
What is the meaning of FRL installed in most pneumatic energy supplies?
Filter, Regulator, Lubricator
Fiber reinforced Lining
Full reservoir level
•Fire Resistance Level
A complete loss of electrical power occur during engine watch. When power is restored, the steering gear pump motor will _________.
have to reset before starting
restart automatically because it utilizes an LVR controller
trip via the overload relay
have to be restart form the steering gear room
Capacitors are measured in ___________.
Farads
Volts
Ohms
Watts
A multimeter may be damaged by taking a _________.
current reading while in the voltmeter mode
voltage reading while in the ammeter mode
resistance reading while in the voltmeter mode
resistance reading while in the ammeter mode
A displacer level sensor uses a ___________.
displacer lighter than the liquid in the process vessel
displacer exactly in weight to the volume of the liquid it displaces
•displacer heavier than the liquid in the process vessel
•displacer that varies in density from top to bottom
Low horsepower, polyphaser, induction motors can be started with full voltage by means of ?
primary-resistor starter
across-the-line starters
compensator starter
auto transformer starters
Ultraviolet light flame scanners installed on an automated main propulsion boiler, are designed so they _________.
are sensitive only to the center of the ultraviolet portion of the flame from a particular burner
might be misled by glowing brick work
cannot be used with steam atomizing burner
will be sensitive to the outer portion of flames
What type of motor wherein as the motor speed is increased, so is the load output, and whose typical application are fans, blowers, centrifugal pumps, mixers and agitators?
Variable torque/Variable HP
Constant torque/Variable HP
Constant HP/Variable torque
Constant HP/Constant torque
What type of motor wherein as the motor speed is increased, so is the load output, and whose typical application are fans, blowers, centrifugal pumps, mixers and agitators?
•Variable torque/Variable HP
•Constant torque/Variable HP
•Constant HP/Variable torque
•Constant HP/Constant torque
The alternating current produced in the generator windings is converted to direct current by the aid of _______.
Rotor and interpoles
commutator and brushes
armature and equalizer
field and exciter
The following are the advantages of hydraulic systems EXCEPT which one?
•Simple and easy overhauling and maintenance of various components
•Usage of comparatively small units
•Permits starting from rest with maximum torque
•Generation and transmission of large forces and powers
Which directional valve can be applied to a pneumatic circuit that requires to keep or ‘memorize’ the last switching position unless an opposite control is given?
•3/2-way push button actuated with pilot air return
•5/2-way single solenoid with spring return
•5/2-way double solenoid directional valve
•3/2-way solenoid actuated with spring return directional valve
If the auto start of the standby motors is correctly set and the no.1 lube oil pump pressure drops while in service, the no. 2 lube oil pump will start automatically and run in/as ?
•back up for no. 1pump
•parallel with no. 1 pump
assist no. 1 pump
•series with no. 1 pump
What is the major advantage of a boiler water DP level measuring system?
Insensitivity to pressure as the method is based on the volume of water in the drum
Insensitivity to foam formation as signal is based on weight of water in the drum
No direct contact with the water in the drum
Does not require process signals from the HP and LP of the boiler
A generator has been exposed to water and is being checked for its safe operation. Therefor, it is necessary to __________.
•Check for shorted coils with a growlers
•Take moisture readings with hydrometer
•Ground the commutator, or slip rings and run it at half load 12 hours
•Test insulation values with a megger
.Which of the following safety device does NOT belong to main engine shutdown trip?
•Control air low pressure
Lube oil low-low pressure
•Thrust bearing high temperature
•Spring air low-low pressure
The conversion of the throttle command voltage to the signal necessary to achieve the desired shaft, PRM is accomplished by _______ .
ahead or astern function generator of the throttle power circuit
operational amplifiers in the auto rotation circuit
feedback resistor of the summing amplifier circuit
ahead or astern function generator of the throttle control circuit
Capacitance in an AC circuit will ?
oppose any change in the circuit voltage
allow current flow in the only one direction
stop current flow once the capacitors is fully charged
rectify the current
How is the operator ensured that he is not in contact with any unearthed conductor before insulation resistance (IR) measurement of a HV system?
•After connecting insulation resistance (IR) tester to the circuit, safety earth is to be disconnected.
Connect the insulation resistance (IR) tester to the conductor with safety earth connection ON
•Comfirm that all the phase are dead using an approved live line tester
•Disconnect the power supply to the HV equipment by opening circuit breaker and opening isolator
Current measuring instrument must always be connected in ?
•Delta with shunt
•Parallel with a circuit
•Series-parallel with a circuit
•Series with a circuit
There are two factors considered in classifying a voltage as “High Voltage”. One is the possibility of causing a spark in air. What is other one?
Magnitude of current flow is too large loads are connected
•Voltage 900V and above
Less extensive with complex networks and connections
•Danger of electric shock contain or proximity
What determines the power factor of an electrical distribution system being supplied by single AC generator?
By prime mover speed
By component of the connected load
By generators rated voltage
By output frequency
When compared to other component in an electric circuit, the Integrated Circuit (IC) is __________.
•Larger, more reliable and less expensive
•Smaller, less reliable and less expensive
•Smaller, more reliable and generally expensive
•Smaller, more reliable, and often less expensive
In the starting system of a large diesel engine, what controls the opening of the remote non-return main starting valve and the cylinder starting valves?
•Slow-turning valve
•Fuel intake system
•Ahead/astern directional valves
•Pilot air system
Electrically charge atoms are called __________.
•valence
•molecule
•ions
•isotope
Pneumatic directional valve symbols consist of either number or capital letters. What letters are applied to the exhaust lines as per ISO/R 1291-1970?
•R,S,T
•A,B,C
•X,Y,Z
•P,P’,P”
On tank vessels with an electrically-driven capstan, the motor should be tested periodically with its ___________.
•armature capacitance
•insulation resistance
•eddy currents
•capacitance
What kind of electrical wiring configuration of a three-phase motor in which each winding is wired end to end to form a completely closed loop circuit, and at each of the three points where the phase are connected, a lead is brought out externally?
•Forward-reverse configuration
•Wye configuration
•Delta-configuration
•Dual-voltage configuration
The electrolyte of Nickel Cadmium battery is __________.
•sulphuric acid
•pure distilled
•potassium hydroxide
•cadmium hydroxide
Which of the following definition best describe sensitivity as a characteristic of controller action?
•The ratio of the output in response to a specified change to the input with cause it.
•The variation of the manipulated variable produced by the mode of control.
•The control point and the value of the controlled variable corresponding to the set point.
•The time difference between the input change and the output change of the controller.
A 5/2-way directional valve has its own return flow from the actuators which can be used for other control purposes. What is best suited to be controlled by this directional valve?
•Rotary pumps
•Double-acting cylinders
•Single-acting cylinders
•Hydraulic motors
Why is it necessary to avoid boiler Low FO temperature and the subsequent alarm?
•Low FO temperature can cause very bright high intensity flame.
•Low FO temperature can cause white smoke on the funnel.
•Low FO temperature can damage the mating surfaces of the FO flowmeter
•Low FO temperature leads to a large amount of unburned fuel accumulation in the furnace.
What electric device is installed for the purpose of cutting off the power if the lines are overload?
•Magnetic coil
•Circuit breaker
•Voltage regulator
•Thermal relay
When charging lead-acid batteries, you should reduce the charging rate as the battery nears its full charge capacity to _______.
•allow equalization of cell voltages
•prevent excessive gassing or over heating
•reduce lead sulfate deposits
•increase lead peroxide formation
Although there are dedicated alarms and trips included with a dedicated water level control system for a marine boiler, It is a standard procedure to check their functioning by verifying actual water level by the ___________.
•water level transmitter
•water level probe sensor
•water gauge glass
•water level capacitance probe
MCB-type circuit breakers are called ___________.
•mechanical contact circuit breaker
•mounted-case circuit breaker
•molded-case circuit breaker
•monoblock-case circuit breaker
Voltage generated by most AC generators is fed machine to the bus by means of __________.
•brushes on slip rings
•slip rings on a commutator
•direct connections from the stator
•brushes on a commutator
The running motor will automatically stop due to the loss of power supply if the blackout occurs and it will start again even without pressing the start push button because of_______ device.
•sequential timer
•remote start circuit
•start button
•auto start circuit
What is the main reason in using an electric megger test essentially for Polarization Index or PI test?
•Because an electronic megger tester will give the most accurate reading
•Because an electronic megger tester can handle higher voltages
Because electronic megger tester does not require battery or external source of energy to energize
•Because hand-driven megger tester will not be able to give the steady test voltage for longer time
The function of the hydraulic telemotor transmitter used in an electro-hydraulic steering gear system is to __________.
•automatically purge all entrained air from the system
•transmit the rudder angle to the bridge indicator
•prevent the control linkage from striking the stops when hand over
•send hydraulic signals to the receiving unit
In a three-phase electrical system, three ground lamps are provided. One lamp goes dark and the others increase in brightness. When the test button is is pressed and all lamps have equal illumination, it means that __________.
•the bright lamp must be replaced
•the dark lamp must replaced
•there is a ground on the line with the bright lamp
•there is a ground on the line with the dark lamp
On an engine throttle control system, the auxiliary control circuits are provided with devices to prevent excessive over travel of the pilot valve by synchronous motor. These devices are called _____.
•three times in a year proximity switches
•overlap relays
•overlap sensors
•limit switches
What is the greatest angle cause of electrical failure?
•breakdown of insulation
•breakdown of conduction
•overcurrent
•high voltage
Starting air valves are opened by the pilot air enabling the compressed air from the receivers to directly enter the engine cylinders. How are these starting valves held closed?
•By air springs
•By helical springs
•By air pistons
•By pilot air
While starting a main propulsion synchronizing motor, the ammeter pegs out at maximum and then returns to the proper value after synchronization. What does this indicate?
•Motor has started properly
•Field windings are grounded
•Slip ring are dirty
•Power transmission cables are grounded
In an electro-pneumatic control system, what component controls the passage of air signals from the input side of the element to the output side?
•Actuator
•Solenoid valve
•Directional control valve
•Check valve
What element is placed inside switch boxes of deck machineries outside the engine worn to avoid short circuit?
•Selica gel
•Absorbent material
•Carbon tetrachloride
•Sodium chloride
The four basic primary levels of an electro-pneumatic system structure are energy supply, input elements, processing elements, and ___________.
•I/P converters
•Actuators
•Transformer
•sensors
What kind of directional valve whose function is to control the direction taken by the fluid flow such that the flow is open in one direction and simultaneously blocked in the other?
•4/2-way directional valve
•Check valve
•3/2-way directional control valve
•5/2-way directional control valve
To avoid damage pulling out a defective PC board connector inside the group starter panel circuit board, it should be kept at ______.
•In line with the circuit board
•Parallel with the circuit board
•An angle with the circuit board
•An angle with the circuit board
Pneumatic directional valve symbol consist of either letters or the numbers 1,2,3,4 and 5 as per DIN ISO 5599. What does the even numbers represent?
•Non-return line
•Exhaust lines
•Control lines
•Working line
What protective device will automatically opens (trip) in case of malfunction in the system?
•No-fuse circuit breaker
•Overload relay
•Over current relay
•Thermal relay
How can you change the speed of the multi-speed, squirrel-cage induction motor opening in a fixed frequency system?
•changing the phase sequence of the applied voltage
•reactance in the circuit must be kept to a minimum
•interchanging stator windings to another poles
•changing the RPM of the rotor flux
A semi-conductor is a material with a _________.
•High conductivity at low temperature
•Conductivity higher than a normal conductor
•Conductivity higher than normal isolator
•Conductivity lower than normal insulator
What is the minimum bus bar clearance between the bottom of enclosure and bus bar?
•6 inches
•4 inches
•2 inches
•10 inches
The efficiency of a diesel engine is greatest at about 80% of maximum load if a CPP is used, at which level, in general efficiency is greater?
•Low pitch and low rpm
•High pitch and low rpm
•High pitch and high rpm
•Low pitch and high rpm
What type of valve installed in series with the water level control valve between the feed water pump and boiler drum?
•Ball valve
•Gate valve
•Butterfly valve
•Check valve
What standard signal, produced by the movement of a metallic strip against a nozzle, is applied to a controller which represents the process variable?
•4~20 mA current
•0.2~1.0 bar air pressure
•1.0~7.0 bar air pressure
•0~5 DC voltage
What kind of transformer wherein the source voltage is higher than the voltage to be supplied?
•Step up
•Step down
•Manual induction
•Convenrtional
How can delicate components to be soldered in a circuit be protected from the heat of the soldering process?
•By opening the soldering gun not more than 60 seconds at a time
•By pre-oxidizing the lead to be soldered.
•By using a thermal shunt
•By coating the leads to be soldered with a light oil film.
Starting valve opening in the correct order and timing is controlled by cams or gear drive from the______.
•engine movement compensator
•engine turning gears
•engine crankshaft
•engine camshaft
What kind of controlling mechanism is being applied to starting air distribution of a diesel engine?
•Electrical motor
•Cams and gear drive from the engine camshaft
•Hydraulic piston
•Manually operated lever
The purpose of DC generator brushes is to .
•Provide excitation to a DC generator
•Neutralize armature reaction
•Conduct electric current to an outside circuit
•Convert DC current to AC current
What determines the power factor of an electric distribution system being supplied by a single AC generator?
•By component of the connected load
•By prime mover speed
•By output frequency
•By generator’s rated voltage
Which of the following is a disadvantage of an AC generator that has a low power factor?
•The gain current increases and produces lower factors
•Current losses in all parts of the machine
•Unable to get maximum kilowatts from the machine
•All motors on the line decrease in power factors
Lead acid battery plate is made-up of ______.
•lead sulphate
•copper
•zinc
•led peroxide
Why is it there is a less chance of making mistake during assembly of integrated circuit because?
•all component are assembled in a step-by-step manner
•all components are glued together
•all components are soldered together so faulty connection is less likely to occur
•all components are installed far apart
What is fitted in the main air line immediately before the air start valve of a large diesel engine to restrict the risk of the flame in the cylinder propagating back to the main air start manifold, by dissipating the heat energy in the flame?
•Spark arrestor
•Flame arrestor
•Flame retardant
•Ignition circular disc
The circuit protection device where the current heats a bimetallic strip which when heated sufficiently bends to allow the trip mechanism to actuate is called the _______.
•Thermal breaker
•Magnetic breaker
•Overload relay
•Voltage regulator
Which of the following safety device belongs to the main engine shutdown trip?
•Overspeed
•Exhaust gas temperature high
•Camshaft LO low pressure
•FO low pressure
According to International regulation, which of the following is true concerning portable cord and fixture wire aboard ship?
•Splices or taps not permitted in cable runs longer than 30 feet
•No splices or taps are permitted
•Soldered splices with electrical tape are permitted
•Solderless crimp-on splices with outside insulation are permitted
What is the purpose of the compressed air regulator of a service unit in a pneumatic control system?
•To keep the operating pressure virtually constant regardless of fluctuations in the line pressure
•To keep primary pressure virtually constant regardless of fluctuations in the operating pressure
•To regulate the oil droplets supplied to the operating line of the pneumatic system
•To regulate the operating pressure according to demand of the system
The solenoid coils on a cargo winch with a electrical brake burns out thus the___________.
•Motor will over speed
•Winch will continue to operate as usual
•Load suspended from the cargo boom will fall
•Brake will be set by spring force
Electron which can be found in the last orbit of an atoms is called _______.
•valence
•neutron
•proton
•ion
Kilowatt load is divided between two DC generators operating in parallel by
•decreasing both prime mover speeds
•adjusting the governor controls
•varying the excitation voltage
•increase both prime mover speeds
Which of the amplifier intended to operate with low-level signals to provide gain and impedance matching to a level that can be handled by another amplifier?
•Processor
•Power amplifier
•Converter
•Pre amplifier
Which of the following statements is correct for electric cables penetrating decks and bulkheads?
•Bushing should be used when passing through deck machinery
•Bushings should be used when passing through deck beams.
Arrangements must be made to ensure fire resistance
•Stuffing tube should be used.
As a practical safeguard against explosions which may occur in a diesel engine crankcase, explosion relief valves doors are fitted. These valve serve to relieve excessive crankcase pressures and stop flames being emitted from the crankcase. What is another requirement and purpose of these relief valves?
•Must have an oil wetted gauze that acts as a flame trap to stop any flames entering the crankcase
•Must be fitted with a locking mechanism to keep it from unwanted functioning while running
•Must be closed manually after the operation once detect is rectified
•Must be self-closing to stop the return of atmospheric air to the crankcase
On the design of apparatus and insulation, which is usually considered as high voltage on board ship based?
•440 volts
•1000 volts
•650 volts
•1100 volts
If boiler blow down is not performed regularly, the following will occur EXCEPT for which one?
•Increased fuel consumption
•Increased accumulation of carbon on the boiler tubes
•Increased thermal stresses within the boiler
•Waste of boiler heat and efficiency
When the voltage and the current in an AC circuit reach their peak value at the same time, the power factor is?
•infinity
•lagging
•leading
•unity
Movement of electrons due to electromagnetism is called ___________.
•Induction
•Thermal conduction
•Inductive effect
•Magnetic effect
If it is needed to covert a signal in one medium to a signal in another, such as pneumatic to electrical of pneumatic to hydraulic, what device should be applied?
•Transmitter
•Controller
•Transducer
•Square root converter
Which of the following type of motors is used where uniform speed, regardless of load, is needed?
•Compound wound motor
•Shunt wound motor
•Series wound motor
•Separately exciter motor
What is the correct procedure to be carried out regarding a small electrical motor that has been submerged in saltwater
Rinse all electrical part with a carbon
•Wash it with fresh water and apply an external of heat.
•Renew the windings.
•Send if shore to an approved service facility.
In the main engine cooling water temperature control, how would be the action of the actuator to keep the desired process temperature?
•The actuator divert all the fluid through the cooler and let the cooler adjust its cooling medium.
•The actuators keeps half open to by-pass and half open to cooler
The actuator diverts the fluid past or through a cooler in controlled manner.
•The actuator diverts all the fluid through the cooler while keeping the steam heating open to the fresh water heater
An assembly of a pneumatic one-way flow control valve consist of a check valve and a _______.
•restrictor
•pneumatic timer
•cushioning valve
•spring
The phase shift between the current and voltage vectors us due to the following except:
•magnet coil
•power capacitor
•fluorescent lamp
•electric flat iron
In a boiler on auto-firing operation, the flame eye detects a flame from the pilot burner and after a set period of time. It sends a signal to the control panel. What does this initiates?
•It energizes the main burner fuel line solenoid valve and opens it.
•It closes fully the air suction damper of the FD fan.
•It stops the atomizing steam of the main burner.
•It supplies air in a controlled condition through the air register in the furnace.
Reactance will cause the current in a circuit to vary only when ?
•have resistance in the circuit
•no current flow
•current flows
•no resistance in the circuit
Pneumatic directional valve symbols consist or either numbers or capital letters. What letters are applied to the control lines as per ISO/R 1291-1970?
•A,B,C
•R,S,T
•U,V,W
•X,Y,Z
What kind of directional valve whose function is to control the direction taken by the fluid flow with flow in both directions and the fluid displaced from the actuator to other control purposes?
•5/2-way directional control valve
•3/2-way solenoid actuated with spring return directional valve
•4/2-way directional control valve
•One-way flow control valve
Reducing the frequency in a capacitative circuit while holding voltage constant will result in a?
•Decrease in circuit current
•Increase in apparent power
•Decrease in total impedance
•Decrease in capacitive reactance
In a AC generator, direct current from a separate source is passed through the windings of the rotor_________?
•by means of a commutator
•by means of slip rings and brushes
•by means of rotating bar magnet
•to minimize the danger of arc over
What does oil mist detector use to measure small increases in oil mist density?
•Vibration cell
•Strain gauge
•Photoelectric cell
•Rectifier diode
On some diesel-electric ships, the DC propulsion motor will only attain half speed when the generator fields are fully excited. Speeds above this are obtained by _______.
•raising the generator engine speed
•decreasing excitation
•lowering the generator engine speed
•rotating brush alignment
Positive ions going to the negative electrode is called _______.
•cations
•electrons
•anions
•proton
Ammeters and voltmeters used in sinusoidal AC power system indicate which of the following values of the waveforms measured?
•Root-mean-square value
•Peak value
•Maximum value
•Average value
What boiler safety device, other than the various alarms and trips, protects the boiler from explosion which designed to relieve internal steam pressure?
•Vent valve
•Safety valve
•Relief valve
•Recirculating valve
Counter EMF is measured in _______.
•amps
•coulombs
•ohms
•volts
In a 5/2-way double solenoid directional valve, what does 5/2 means?
•5 port double solenoid
•5 ports with 2 exhaust connections
•5 ports 2 switching positions
•5 switching positions, 2 ports
In order to protect the generator in service from overload, the non-essential load is isolated from the system by what device?
•Preferential tripping system
•Main circuit breaker tripping system
•No fuse breaker tripping system
•Automatic voltage trip regulator
In a boiler auto-firing operation, what is the next sequence after the completion of the pre-purging operation?
•Post-purging operation is initiated.
•Fuel is supplied to the main burner.
•Power is supplied to the electrode of the pilot burner.
•Fuel is supplied to the pilot burner.
Effects of electron movement are both the same regardless of the direction of ________.
•Cycle
•Current flow
•Magnetic effect
•Alternating current
Which of the following refers to a bipolar transistor which utilizes an N-type region which is sandwiched between two P-type regions?
•PIN transistor
•NPN transistor
•PNP transistor
•Basic transistor
Why is it necessary to measure bolted bus bar joint resistance?
•Because high current flows through the bus bar, current may leak the ground
•Because as high current flows through the bus bar, any resistance in it causes resistive heating
•Because the nut and bolts could get loose time and cause abnormally high resistance
•Because the bolted joints surfaces can deteriorate and cause different values over time
In the general, Zener diodes can dissipate more if its leads are______.
•elongated
•extended
•shortened
•prolonged
An alloy of copper and nickel used for thermometer is called _________.
•constantant
•steel
•chromel
•alumel
Since fuse elements are made of zinc or any alloy of tin and lead, the melting point of the fuse element must be .
•Higher than that copper
•Equal to that of copper
•Reached when the conductor it is protecting becomes \’white hot.\’
•Lower than that of copper
What type of level control system is fitted either on the top of the boiler drum or in a water chamber attached to a metal rod which activates magnetic switches for starting or stopping the pump or opening and closing of the feed valve?
•Level control float type
•Differential pressure level control type
•Level control probe type
•Linear variable differential transformer type
Arrange the correct sequence of procedure for measuring insulation resistance of a HV equipment as described below. I. Close the earthing switch and make sure all the conductors are earthed. II. Confirm that all the phase are dead using an approved live line tester. III. After connecting insulation resistance (IR) tester to the circuit, safety earth is to be connected. IV. Insulation resistance (R) test is applied and recorded. V. Connect the insulation resistance (IR) tester to the conductor with safety earth connection ON. VI. Disconnect the power supply to the HV equipment by opening circuit breaker and opening isolator.
•II>I>V>VI>III>IV
•VI>I>V>III>II>IV
•VI>II>I>V>III>IV
•I>II>III>IV>V>VI
Which of the method listed is used to maintain equal load sharing between two compound wound DC generators operating in parallel?
•The series field both generators are connected in parallel
•The series field of both generators are connected in series
•The shunt field are interconnected
•The shunt field rheostats are interconnected
How can the hot spots in the bus or surrounding are be checked safety?
•By using a portable thermometer with long sensor probe
•By using Rayteck gun
•By visual inspection
•By using infra-red thermal imaging device
The different between the synchrosnouse speed of an induction machine and its operating speed (slip) may be correctly expressed as ______.
•a series wound motor
•a directly in revolutions per minute
•a decimal fraction of synchronous speed
•a percent of synchronous speed
What type of level system where metal rod is suspended in the boiler water drum with electrical voltage along with an ammeter included in the circuit which can be used to control starting and stopping of the feed water pump or to open the feed water valve integrated with the level alarm?
•Linear variable differential transformer
•Level control float type
•DP transmitter level switch
•Level control probe type
What electric device is being connected between two generators of different capacities rubbing parallel so that the running load is devided proportionally between the two?
•Power supply
•Voltage regulator
•Rheostat
•Equalizer
What device consist of timing valves synchronized with the engine position in order to provide air to operate each starting valve in the correct order and timing as the engine rotates?
•Air distributor
•Slow-turning valve
•Remote main starting valve
•Starting air solenoid valve
In paralleling of two generators, what does it indicates if the synchronizing lamps remain lighted as the synchroscope pointer approaches the zero degree position?
•the flow of power is in reverse direction
•the voltage reading of incoming generator is lower than 440 volts
•two generator are in phase
•two generators are in parallel
The true power indicated by the pointer movement of a wattmeter depends on the current flow through the load, the magnitude of the potential across the load, and the ?
•angle of coil displacement
•inertia of the movable coil
•high resistance from the load
•power factor of the load
The most common source of excitation for synchronous motors is a/an.
•AC supply
•DC supply
•Step up transformer
•half-wave rectifier
Pneumatic directional valve symbols consist of either or numbers 1,2,3,4 and 5 as per DIN ISO 5599. What does the odd numbers represent?
•Non-return valve
•Working lines
•Exhaust lines
•Quick-exhaust lines
When choosing a battery for a particular, major consideration should be given to the battery’s?
•stability under charge
•terminal polarity
•amp-hour capacity
•ambient temperature
A two-position single-point action controller has been adjusted to minimize cycling and would only be suitable for ?
•wide temperature fluctuation
•intermittent load conduction
•constant load conditions
•rate action only
Which of the following is true when a conductor reactance is compared to an alternating current relative to the flow in a resistance?
•Higher
•Lower
•The same
•Fluctuating
An accidental path of low resistance, allowing passage of abnormal amount of current is known as a/an _______.
•Polarized ground
•Ground reference point
•Open circuit
•Short circuit
When charging lead-acid batteries, you should reduce the charging rate as the battery nears its full charge capacity to.
•allow equalization of cell voltages
•prevent excessive gassing and overheating
•increase lead peroxide formation
•reduce lead sulfate deposits
The power supply of a megger is obtained from _________.
•batteries
•any 115 volt AC circuit
•any 115 volt DC circuit
•a magneto
One method of testing for a reversed shunt field coil in a DC generator or motor is by connecting the field to a direct current source, at reduced filed rated voltage. And test for polarity using a/an _______.
•test lamp across adjust field
•magnetic compass placed near each field
•copper jumper across the interpole connections
•iron bar across each field
The loop of wire that rotates through and cut the magnetic field in a generator is called ______.
•carbon brushes
•armature
•slip ring
•poles
In an electro-hydraulic steering gear, any change in negative position between the synchronous receiver and the follow-up gear will result in ?
•the pump going to full stroke
•a corresponding slowing or increasing of the pumped flow rate
•closing of the six-way valve
•driving the rams up against the stops
Pneumatic directional valve symbols consist of either numbers of the letters A, B, C, P, R, S, T, X, Y an Z as per ISO/R 1219-1970. What does the letter A, B, and C represent?
•Non-return lines
•Exhaust lines
•Control lines
•Working lines
Moisture damage, as a result of corresponding occurring inside of the cargo winch master switches, can be reduced by?
•venting the switch box regularly
•using a strip heater inside the switch box
•coating the switch box internals with epoxy sealer
•installing light bulb in the pedestaal stand
The total resistance of a parallel circuit is always _________.
•unequal to the sum of the individual branch resistance
•equal to the sum of the individual branch resistance
•larger than that of the branch with greatest resistance
•smaller than that of the branch with the lowest resistance
The calculate the Volts Amperes (VA), what do you need to know?
•resistance and impedance
•impedance and conductance
•ohms and resistance
•voltage and current
To ensure boiler is operated at high efficiency, what should the best feed water temperature setting of the temperature controller?
•60 ~ 65 deg C
•80 ~ 85 deg C
•55 ~ 60 deg C
•90 ~ 95 deg C
The purpose of the commutator and brushes on a DC generator is to ______.
•provide a sliding method to excite the field
•transfer generated direct current voltage from the armature to the line
•reduce sparking between the armature and the carbon brushes
•convert the alternating voltage within the armature to a direct voltage
What alarm is initiated causing the feed water pump to stop, cutting water supply to the boiler drum, preventing the drum from excessive pressure exerted by the feed water, which may explode the boiler drum or at least, weaken it?
•High steam pressure alarm
•High-high water level alarm
•High water level alarm
•Low atomizing steam pressure alarm
What electrical device will avoid any action that may happen unless all other conditions are met?
•monitor
•interlock
•modulator
•limit
If the main propulsion diesel governor works irregularly with a jerking motion, a possible cause can be?
•Excessive pressure in the seawater feed heater
•A constant quality regulating valve
•95 degrees Celsius
•A sticking fuel control linkage
What control signals are being applied to an electro-pneumatic 3/2-way directional valve that automatically returns it to original position once de-activated?
•Solenoid and roller
•Push button and lever
•Solenoid and spring
•Pilot air and spring
. A testing device called a “growler” is being used to locate a shorted coil in the stator of an AC electrical machine. When “feller” is moved over a slot containing the shorted coil?
•the meter needle will be depleted to full scale
•a loud growling noise will be heard
•any vibration within the feller will cease
•the meter needle will be depleted to zero
The alarm system for an engine order telegraph uses small selsyn motors attached to the indicators. The alarm sounds when the rotors are _______.
•not synchronized, current is flowing, and the relays are closed
•in synchronous position, no current is flowing, and the relays are closed
•not synchronized, current is flowing, and the relays are open
•in synchronous position, non current is flowing, and the relays are open
What alarm prevents the accumulation of fuel into the furnace which may become the source of explosion if not properly purged? This alarm is over ridden during starting up/firing up of the boiler.
•Low combustion air pressure alarm
•Flame failure alarm
•High water level alarm
•Low atomizing steam pressure alarm
.As the designated rudder angle is being activated, as a result of the original command input, the steering gear follow-up mechanism is____.
•In motion, providing a null input
•In motion, providing an input to place the main pump at null stroke
•In motion, providing an input to place the main pump on maximum stroke
•Not in motion, thus providing a null input
What is indicated as the original bridge gage reading for a reduction gear bearing which was originally measured .008 inches, then a year later, the gage reading for the bearing is 0.010 inches?
•Bearing wear has increased
•Renewal of bearing needed
•Bearing wear is 0.002 inch
•Oil clearance has increased , 0.010 inch
Hydrostatic pressure of a liquid column depends on _______.
•Height of the liquid column and its density
•Volume of the liquid in the reservoir
•Only the specific gravity of the liquid
•Shape of the reservoir
In a AC synchronous motor electric propulsion plant, propeller speed controlled by varying the _____.
•number of energized main motor poles
•prime mover speed
•propulsion generator field strength
•electric coupling field strength
What kind directional valve whose function is to control the direction taken by the fluid flow by shutting off or opening the passage?
•3/2-way directional control valve, normally open
•4/2-way directional control valve
•3/2-way directional control valve, normally close
•2/2-way directional control value
Which of the following statements correctly applies to transistors?
•The collector separates the emitter, and base
•The three terminals are called the emitter, base, and collector.
•NDN an PNP are two basic types of transistors.
•The emitter separates the base and collector.
Which of the following safeguards can be built into the control circuits of a remotely operated fire pump to ensure that the pump is not started with the suction valve closed?
time delay relay is de-energized when the ON button is pushed, and the pump starts after a predetermined time
•A contact in the suction valve open-starter coil opens and the pump starts immediately
•A normally open contact closes in the fire pump suction valve starter coil circuit.
•Starting circuit is engaged by a limit switch when the suction valve opens.
In using a fuse whose rating is higher than necessary will__________.
•increase the efficiency of the apparatus
•increase the efficiency of the apparatus
•waste money because they are more expensive
•reduce the possibility of fuse getting blown
•endangers the apparatus it is supposed to protect
What is the advantage of a higher-voltage system as compared as compound of a lower-voltage system?
•Reduced power source.
•Large currents.
•Lower electrical pressure.
•Reduced voltage drop.
What does a low system power factor in an alternating current electrical system directly indicates?
•a short in exciter field windings
•a large resistance load
•a large inductive load
•a ground in exciter field windings
The D.C generator where the output is used to supply the field is called_______.
•shunt
•separately excited
•self excited
•compound
How does a puncture valve function in stopping the main engine or during shutdown?
•It introduces HP compressed air to the reversing cylinder to apply brake on the engine.
•It cuts-off the HP fuel by closing the inlet ball valve using compressed air from the stop directional valve.
•It reduces the high pressure of the fuel oil by connecting the HP side to the pump body, thereby sopping the injection of the fuel.
•It lifts the fuel cam follower from the cam nose so that no fuel pumping can occur.
All transformers have the same operating principles and characteristics, and every transformer has a primary winding and ______.
•secondary winding
•core winding
•main winding
•auxiliary winding
The load sharing characteristics of two diesel operating in parallel are mostly dependent on their governor _____.
•speed limit settings
•idle speed settings
•speed droop settings
•load limit settings
The electro-pneumatic circuit layout follows the signal flow through the control chain from bottom to top. However, the electric elements are numbered following the direction of signal flow from ________.
•bottom to top
•right to left
•left to right
•top to bottom
In a diesel electric plant, raising the generator’s field excitation will cause the DC propulsion motor to.
•decrease in speed
•affect generator speed only
•affect main motor speed if done in conjunction with higher generator engine speeds
•increase in speed
What kind of directional valve whose function is to control the direction taken by the fluid flow with flow in both directions?
•3/2-way solenoid actuated with spring return directional valve
•4/2-way directional control valve
•2/2-way directional control valve
•5/2-way single solenoid with spring return
What is the cause of presence of an oil mist in the diesel crankcase that can result to explosive condition if build is allowed?
•Oil vaporization caused by hot spot
•Lowered TBN of the crankcase system oil
•Leakage of fuel and lube oil mix thru the stuffing box
•Damaged main bearing temperature sensor
What main engine safety detecting device uses a motor driven fan and a rotary valve that continuously draws samples through a measuring tube and compares it
•Fuel oil viscosity controller
•Lube oil differential pressure gauge
•Oil mist detector
•Scavenging limit transmitter
