WorksheetsFUNCTION 2 (C5)
Total questions: 217
Worksheet time: 4hrs 37mins
The phase shift between the current and voltage vectors us due to the following except:
electric flat iron
magnet coils
power capacitor
fluorescent lamp
Why is there is a less chance of making mistake during assembly of an integrated circuit because _
all components are installed far apart
all components 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
Pneumatic directional valve symbols consist of either numbers or capital letters. What letters are applied to the control lines as per ISO/R 1291-1970?
X, Y, Z
R, S, T
U, V, W
A, B, C
In the generator synchronizing board, circuit breaker's closing operation of an incoming generator is done when the synchronizing lamp indicator is at the _
90 before reaching the top cycle
no indication
top part of the cycle
bottom part of the cycle
Lead acid battery positive plate is made-up of _
Zinc
Lead peroxide
Copper
Lead sulphate
A medium pressure water tube boiler uses a level differential pressure transmitter to detect the actual level inside the drum. What signals are applied to the transmitter in order to detect the process parameter?
Main steam drum and steam flow pressures
Pressure from the steam side of the boiler
Pressure from the water side of the boiler
Pressure from the HP and LP side of the steam drum
Which among the below systems on board applies an open-loop control system?
Auxiliary engine RPM control
System for remote opening and closing the engine room dampers
Boiler water level control system
Steering gear system
The most common source of excitation for synchronous motors is a/an _
DC supply
AC supply
stepup transformer
half-wave rectifier
On the design of apparatus and insulation, which is usually considered as high voltage on board ship based?
1000 volts
440 volts
1100 volts
650 volts
What is the main reason win using an electronic megger tester essentially for Polarization Index or PI test?
Because hand-driven meager tester will not be able to give the steady test voltage for longer time
Because electronic merger tester does not require batter or external source of energy to energize
Because an electronic merger tester will give the most accurate reading
Because an electronic merger tester can handle higher voltages
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?
Set point
Neutral zone
Offset
Control point
The differential pressure signal, either electrically or pneumatically, corresponds to the water level in the boiler. 0% level corresponds to 4 mA while 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
12 mA
18 mA
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 _
Magnetic breaker
Thermal breaker
Overload relay
Voltage regulator
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 spring
Pilot air and spring
Solenoid and roller
Push button and lever
Why is it necessary to measure bolted bus bar joint resistance?
Because as high current flows through the bus bar, current may leak to the ground
Because the nuts and bolts could get loose over time and cause abnormally high resistance
Because the bolted joints surfaces can deteriorate and cause different resistance values over time
Because as high current flow through the bus bar, any resistance in it causes resistive heating
In an AC generator, direct current from a separate source is passed through the windings of the rotor _
by means of slip rings and brushes
to minimize the danger of arc over
by means of rotating bar magnet
by means of a commutator
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?
Remote main starting valve
Air distributor
Slow-turning valve
Starting air solenoid valve
What is the cause of presence of an oil mist in the diesel engine crankcase that can result to explosive condition if buildup is allowed?
Lowered TBN of the crankcase system oil
Oil vaporization caused by a hot spot
Damaged main bearing temperature by a hot spot
Leakage of fuel and lube oil mix through the stuffing box
The alarm system for an engine order telegraph uses small selsyn motors attached to the indicators. The alarm sound when the rotors are _
not synchronized, current is flowing, and the relays are open
in synchronous position, no current flowing, and the relays are open
not synchronized, current is flowing, and the relays are closed
in synchronous position, no current is flowing, and the relays are closed
What kind of directional valve whose function is to control the direction taken by the fluid flow by shutting off or opening the passage?
2/2-way directional control valve
4/2-way directional control valve
3/2-way directional control valve, normally close
3/2-way directional control valve, normally open
Ultraviolet light sensing 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
cannot be used with steam atomizing burners
might be misled by glowing brick work
will be sensitive to the outer portion of flames
Ultraviolet light sensing 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
cannot be used with steam atomizing burners
might be misled by glowing brick work
will be sensitive to the outer portion of flames
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?
overheated crosstie busses
excessive vibration of the vessel
tripped main motor interlocks
closed contact in the field circuits
Pneumatic directional valve symbols consist of either numbers or the letters A, B, C, P, R, S, T, X, Y, and Z as per IOS/R 1219-1970. What does the letter A, B, and C represent?
Exhaust lines
Control lines
Non-return lines
Working lines
Pneumatic directional valve symbols consist of either numbers or the letters A, B, C, P, R, S, T, X, Y, and Z as per IOS/R 1219-1970. What does the letter A, B, and C represent?
Exhaust lines
Control lines
Non-return lines
Working lines
Which of the following is a disadvantage of an AC generator that has a low power factor?
All motors on the line decrease in power factors
The gain current increases and produces lower power factors
Current losses in all parts of the machine
Unable to get maximum kilowatts from the machine
In paralleling two generators, what does it mean when 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 440V
Two generators are in phase
Two are in parallel connection
The alternating current produced in the generator windings is converted to direct current by the aid of _
commutator and brushes
armature and equalizer
field and exciter
rotor and interpoles
Ammeters and voltmeters used in sinusoidal AC power systems indicate which of the following values of the waveforms measured?
Root-mean-square value
Average value
Maximum value
Peak value
Pneumatic directional valve symbols consist of either letters or the numbers 1, 2, 3, 4, and 5 as per DIN ISO 5599. What does the odd numbers represent?
Working lines
Quick-exhaust lines
Exhaust line
Non-return lines
The main engine reversing mechanism is tested by repeated changes from ahead to astern and vice-versa where after each change, the engine is started. What does this test provide?
information on the durability of the main starting valves after successive starts
information concerning the minimum starting air pressure at which reversing and starting can be accomplished
information of how much reduction of starting air pressure at every start
information on how fast the main air compressors can fill the air
Which of the following statements is correct to determine the need of cleaning the electric motor wiring?
High merger readings
Visual inspecting for dirt accumulation
Low operating temperature
Efficiency has increased
What is the advantage of a higher-voltage system as compared to a lower-voltage system?
Lower electrical pressure
Large currents
Reduced power source
Reduced voltage drop
In the main engine cooling water temperature control, how would be the action of the actuator to keep the desired process temperature?
The actuator diverts all the fluid through the cooler and let the cooler adjust its cooling medium
The actuator diverts all the fluid through the cooler while keeping the steam heating open to the fresh water heater
The actuator diverts the fluid past or through a cooler in a controlled manner
The actuator keeps half open to by-pass and half open to cooler
Which of the following is true when a conductor reactance is compared to an alternating current relative to the flow in a resistance?
Fluctuating
The same
Lower
Higher
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 _
decreasing excitation
rotating brush alignment
lowering the generator engine speed
raising the generator engine speed
What determines the power factor of an electrical distribution system being supplied by a single AC generator?
By generator's rated voltage
By components of the connected load
By prime mover speed
By output frequency
The electrolyte of Nickel Cadmium battery is _
sulphuric acid
pure distilled water
potassium hydroxide
cadmium hydroxide
To avoid damage in pulling out a defective PC board connector inside the group starter panel circuit board, it should be kept at _
opposite with the circuit board
in line with the circuit board
parallel with the circuit board
an angle with the circuit board
What kind of controlling mechanism is being applied to the starting air distributor of a diesel engine?
Manually operated lever
Hydraulic piston
Electrical motor
Cams and gear drive from the engine camshaft
What standard signal, produced by the movement of a metallic strip against a nozzle, is applied to a controller which represents the process variable?
0-5 DC voltage
1.0-7.0 bar air pressure
0.2-1.0 bar air pressure
4-20 mA current
Moisture damage, as a result of condensation occurring inside of the cargo which master switches, can be reduced by _
installing a light bulb in the pedestal stand
coating the switch box internals with epoxy sealer
using a strip heater inside the switch box
venting the switch box regularly
The solenoid coils on cargo which with an electrical brake burns out thus the _
winch will continue to operate as usual
motor will over speed
load suspended from the cargo
brake will be set by spring force
Reactance will cause the current in a circuit to vary only when _
no current flow
no resistance in the circuit
have resistance in the circuit
current flows
What is the purpose of the compressed air regulator of a service unit in a pneumatic control system?
To regulate the operating pressure according to demand of the system
To keep the 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 keep the operating pressure virtually constant regardless of fluctuations in the line pressure
What is the major advantage of boiler water DP level measuring system?
insensitivity to pressure as the method is based on the volume of water in the drum
Does not require process signals from the HP and LP side of the boiler
Insensitivity to foam formation as signal is based on weight of water in the drum
No direct contact with the water in the drum
What boiler safety device, other than the various alarms and trips, protects the boiler from explosion which is designed to relieve internal steam pressure?
Safety valve
Recirculating valve
Relief valve
Vent valve
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 field rated voltage, and test fro polarity using a/an _
copper jumper across the interpose connection
magnetic compass placed near each field
iron bar across each field
test lamp across adjacent field
On a main switchboard, if all three ground detection lamps remain lifted at half intensity when the test button is depressed, which of the listed conditions will be indicated?
All three phases are grounded
No earth fault exist
The current transformers are shorted
The test switch is grounded
What kind of transformer wherein the source voltage is higher than the voltage to be supplied?
Mutual induction
Step up
Conventional
Step down
Which battery charging circuits is used to maintain a wet-cell, lead-acid, ad storage battery?
Trickle charging circuit
inverter
Power charging station
Bulk charging unit
What type of motor wherein as the motor speed is increased, so is the load output, and whose typical applications are fans, blowers, centrifugal pumps, mixers, and agitators?
Constant HP/Variable torque
Variable torque/Variable HP
Constant torque/Variable HP
Constant HP/Constant torque
In an AC synchronous motor electric propulsion plant, propeller speed is controlled by varying the _
number of energized main motor poles
electric coupling field strength
propulsion generator field strength
prime mover speed
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 generated armature reaction. These changes in armature reaction are compensated for by the _
voltage regulator
balance coil
governor speed droop setting
phase-balance relay
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 valve?
Slow-turning valve
Ahead/Astern directional valves
Pilot air system
Fuel linkage system
An assembly of a pneumatic one-way flow control valve consist of a check valve and a _
restrictor
spring
cushioning valve
pneumatic timer
What protective device will automatically opens (trip) in case of malfunction in the system?
Over current relay
Thermal relay
No fuse circuit breaker
Overload relay
If the auto start of the standby motor 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 _
parallel with no. 1 pump
assist no. 1 pump
series with no. 1 pump
back up for no. 1 pump
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 stops the atomizing steam of the main burner
it energizes the main burner fuel line solenoid valve and opens it
it supplies air in a controlled condition through the air register in the furnace
it closes fully the air suction damper of the FD fan
The load sharing characteristics of two diesel generators operating in parallel are mostly dependent non their governor _
speed limit settings
speed droop settings
idle speed settings
load limit settings
A testing device called a "growler" is being used to locate a shorted coil in the stator of an AC electrical machine. When the "feeler" is moved over a slot containing the shorted coil _
the meter needle will be depleted zero
any vibration within the feeler will cease
the meter needle will be depleted to full scale
a loud growling noise will be heard
What is the function of the main engine running direction interlock?
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 roller of fuel pump have shifted
It prevents the engine from starting in reverse direction until all the cam rollers of exhaust valve have shifted
It prevents the engine from starting in reverse direction until all air distributor valves have shifted
Pneumatic directional valve symbols consist of either numbers or capital letters. What letter are applied to the exhaust lines as per ISO/R 1291-1970?
A, B, C
X, Y, Z
P, P, P
R, S, T
In a diesel electric plant, raising the generator's field excitation will cause the DC propulsion motor to _
affect generator speed only
affect main motor speed if done in conjunction with higher generator engine speeds
decrease in speed
increase in speed
Effect of electron movement are both the same regardless of the direction of _
Cycle
Current flow
Magnetic effect
Alternating current
In an electro-hydraulic steering gear system, when will the variable displacement pump be placed on stroke?
When the ridder angle is different from the position of the helm
When the ram relief valves lift
When the six-way valve is opened
When the helm is at any angle other than amidships
As the designated rudder angle is being achieved, as a result of the original command input, the steering gear follow-up mechanism is _
not in motion, thus providing a null input
in motion, providing an input to place the main pump on maximum stroke
in motion, providing an input to place the main pump at null stroke
in motion, providing a null input
Counter EMF is measured in _
volts
ohms
amps
coulombs
A multimeter ma be damaged by taking a _
resistance reading while in the ammeter mode
voltage reading while in the ammeter mode
current reading while in the ammeter mode
resistance reading while in the voltmeter mode
The purpose of DC generator brushes is to _
convert DC current to AC current
neutralize armature reaction
provide excitation to a DC generator
conduct electric current to an outside circuit
What is the correct procedure to be carried out regarding a small electrical motor that has been submerged in saltwater?
Send it shore to an approved service facility
Rinse all electrical parts with a carbon
Renew the windings
Wash it with fresh water and apply an external source of heat
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 same bearing is 0.010 inches?
renewal of bearing needed
bearing wear has decreased
bearing wear is 0.002 inch
oil clearance has increased 0.010 inch
The simplest method of controlling the terminal voltage of compound-wound DC generator is with a _
carbon pile regulator in series with the load
hand-operated field rheostat connected in series with the shunt field circuit
balance coil diverting neutral current through the shunt field
separate exciter in a series with the shunt field
A complete loss of electrical power occur during engine watch. When power is restored, the steering gear pump motor will _
have to reset before restarting
trip via the overload relay
have to be restarted form the steering gear room
restart automatically because it utilizes an LVR controller
Electrically charged atoms are called _
valence
ions
isotope
molecule
What instrument is used in order to adjust the combustion air fuel ratio of the boiler accordingly?
Smoke density sensor
Flue gas analyzer
CO analyser
Ringleman scale
The following are the advantage of hydraulic systems EXCEPT which one?
Permits starting from rest with maximum torque
Usage of comparatively small units
Simple and easy overhauling and maintenance of various components
Generation and transmission of large forces and powers
If the relay coil is not "on" when it indicates that is should be energized with rated voltage measured across the coil is present, probably the cause would be?
Auxiliary contact in series with coil
Coil is open
Fuse is shown
Transformer is defective
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 and in parallel with the meter movement
series with the load and in series with the meter movement
parallel with the load and in series with the meter movement
An accidental path of low resistance, allowing passage of abnormal amount of current is known as a/an _
polarized ground
ground reference point
short circuit
open circuit
Negative ions going to the positive electrode is called
electron
cations
anions
proton
What is the most inefficient method of voltage reduction from the stand point of power loss?
inductor in series with the load
capacitor in series with the load
resistor in series with the load
capacitor and inductor in series with the load
The four basic primary levels of an electro-pneumatic system structure are energy supply, input elements, processing elements, and _
actuators
sensors
I/P converters
transducers
If boiler blow down is not performed regularly, the following will occur EXCEPT for which one?
Increased accumulation of carbon deposits on the boiler tubes
Waste of boiler heat and efficiency
Increased fuel consumption
Increased thermal stresses within the boiler
In HV system IR measurement, what should be the range of the merger tester to be used for up to 6.6 kV?
10,000 VDC merger
5,000 VDC merger
1,000 VDC merger
1,000 VAC merger
How can the hot spots in the bus bars or surrounding area be checked safely?
By using Rayteck gun
By visual inspection
By using a portable thermometer with long sensor probe
By using intfrared thermal imaging device
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 phases are connected, a lead is brought out externally?
Wye configuration
Delta configuration
Dual-voltage configuration
Forward-reverse configuration
Electron which can be found in the last orbit of an atom is called _
valence
proton
neutron
ion
Silicon diodes designed for a specific reverse breakdown voltage, become useful as an electronic power supply voltage regulator, is called _
compensating diodes
tunnel diodes
hot-carrier diodes
Zener diodes
Hydrostatic pressure of a liquid column depends on _
volume of the liquid in the reservoir
height of the liquid column and its density
shape of the reservoir
only the specific gravity of the liquid
What safety device prevents the opening of the remote main starting non-return valve if the engine turning gear is engaged?
Sequence valve
Interlock
Puncture valve
Proximity switch
Low horsepower, polyphase, induction motors can be started with full voltage by means of _
compensator starter
primary-resistor starter
auto transmitter starters
across-the-line starters
What will be the phase angle relationship of a six-pole, three-phase, rotating field generator?
60°
180°
120°
360°
Starting valve opening in the correct order and timing is controlled by cams or gear drive from the _
engine moment compensator
engine timing gears
engine camshaft
engine crankshaft
In a diesel engine starting air system, from the air receiver, where is the compressed air for starting supplied first before the cylinder air starting valve?
Starting air distributor
Ahead or astern directional valve
Starting solenoid valve
Automatic main starting valve
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 control valve
3/2-way directional control valve
5/2-way directional control valve
Check valve
A two-position single-point action controller has been adjusted to minimize cycling and would only be suitable for _
rate action only
intermittent load conditions
wide temperature fluctuations
constant load conditions
An operating characteristic appearing on the name plates of shipboard AC motors is _
the type of winding
rated slip
locked rotor torque
temperature rise
The function of the hydraulic telemeter 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
send hydraulic signals to the receiving unit
prevent the control linkage from striking the stops when hard over
What kind of directional valve whose function is to control the direction taken by the fluid flow with flow in both directions?
4/2-way directional control valve
3/2-way solenoid actuated with spring return directional valve
2/2-way directional control valve
5/2-way single solenoid with spring return
As a practical safeguard against explosions which may occur in a Diesel engine crankcase, explosion relief valves or doors are fitted. These valves serve to relieve excessive crankcase pressures and stop flames being emitted from the crankcase. What is another requirement and purpose for these relief valves?
Must be self-closing to stop the return of atmospheric air to the crankcase
Must have an oil wetted gauze that acts as a flame trap to stop any flames entering the crankcase
Must be closed manually after operation once the defect is
Which of the following is an amplifier intended to operate with low-level signals to provide gain and impedance matching to a level that can be handled by another amplifier?
Pre-amplifier
Converter
Processor
Power amplifier
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 service mode
in service mode
running mode without load
standby mode
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 phases are dead using an approved live line tester
III) After connecting insulation resistance (IR) tester to the circuit, safety earth is to be disconnected
IV) Insulation resistance (IR) 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
I > II > III > VI > V > IV
II > I > V > VI > III > IV
VI > I > V > III > II > IV
VI > II > I > V > III > IV
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 _
power factor of the load
inertia of the movable coil
angle of coil displacement
high resistance from the load
What electric device is being connected between two generators of different capacities running parallel so that the running load is divided proportionally between the two?
Rheostat
Voltage regulator
Equalizer
Power relay
When charging lead-acid batteries, you should reduce the charging rate as the battery nears its full charge capacity to _
reduce lead sulfate deposits
prevent excessive gassing and overheating
increase lead peroxide formation
allow equalization of cell voltages
Which of the following is the Japanese International Standard (JIS) markings in electrical equipment and is recognized by the Japanese class society?
NK
Nippon Koyo
Nippon Kusen
Nippon Go
Kilowatt load is divided between two DC generators operating in parallel by _
decreasing both prime mover speeds
increase both prime mover speeds
varying the excitation voltage
adjusting the governor controls
In a three-phase electrical system, three ground detecting lamps are provided. One lamp goes dark and the others increase in brightness. When the test button is pressed and all lamps have equal illumination, it means that _
there is a ground on the line with the dark lamp
there is a ground on the lines with the bright lamp
the bright lamp must be replaced
the dark lamp must be replaced
If it is needed to convert a signal in one medium to a signal in another, such as pneumatic to electrical or pneumatic c to hydraulic, what device should be applied?
Transmitter
Square root converter
Controller
Transducer
What type of level control system where a 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 arm?
Level control probe type
DP transmitter level switch
Level control float type
Linear variable differential transformer type
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
Basic transistor
NPN transistor
PNP transistor
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?
A normally open contact closes in the fire pump suction valve starter coil circuit
A time delay relay is de-energized when the "ON" button is pushed, and the pump starts after a predetermined time
Starting circuit is engaged by a limit switch when the suction valve opens
A contact in the suction valve open-starter coil opens and the pump starts immediately
How can a delicate component to be soldered in a circuit be protected from the heat of the soldering process?
By coating the leads to be soldered with a light oil film
By pre-oxidizing the leads to be soldered
By using a thermal shunt
By operating the soldering gun not more than 60 seconds at a time
An alloy of copper and nickel used for thermocouple is called _
alum
chrome
steel
constantan
Why is it necessary to avoid boiler Low FO temperature and the subsequent alarm?
Low FO temperature can cause white smoke on the funnel
Low FO temperature can cause very bright high intensity flame
Low FO temperature leads to a large amount of unburned fuel accumulation in the furnace
Low FO temperature can damage the mating surfaces of the FO flowmeter
Current used primarily because it can be transmitted inexpensively and because it can be use for application for which the current is not suitable?
Direct current
Electric charge
Electricity
Alternating current
How can you change the speed of a multi-speed, squirrel-cage induction motor operating in a fixed frequency system?
reactance in the circuit must be kept to a minimum
changing the phase sequence of the applied voltage
changing the RPM of the rotor flux
interchanging stator windings to another poles
The DC generator where the output us used to supply the field current is called _
self excited
shunt
separately excited
compound
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 cylinder starting valve and remote starting air valve
to the remote starting air valve first
to the starting air distributor first
simultaneously to the remote starting air valve and air distributor
What does a low system power factor in an alternating current electrical system directly indicates?
a large inductive load
a short in exciter field windings
a large resistance load
a ground in exciter field windings
Why is copper loads and iron loss less in high voltage system?
Because the current carrying capacity of conductor increases in HV installation
Because the copper and iron are the best conductors for HV installation
Because the current draw with HV is much less
Because the conductor's cross-sectional area is reduced in HV installation
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?
Solenoid valve
Actuator
Directional control valve
Check valve
A forward-biased diode acts like a switch that is _
capacitor
closed
relay
open
The most common source of excitation for synchronous motors is a/an _
AC supply
low voltage battery
DC exciter generator
motor attenuator set
Voltage generated by most AC generators is fed from the machine to the bus by means of _
brushers on slip rings
direct connections from the stator
brushes on a commutator
slip rings on a commutator
Which of the following safety devices does NOT belong to main engine shutdown trip?
Spring air low-low pressure
Lube oil low-low pressure
Thrust bearing high temperature
Control air low pressure
What electrical device will avoid any action that may happen unless all other conditions are met?
interlock
monitor
limit
modulator
In a standard motor starter panel, a motor is started by pressing the start push button switch. This energizes a starting relay and a _
transformer
starter relay
contactor
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
increase lead peroxide formation
reduce lead sulfate deposits
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 a timer switch. During this purging sequence, what is the position of the FD fan air suction damper?
50% open
100% open
100% close
25% open
What electric device is installed for the purpose of cutting off the power if the lines are overloaded?
Voltage regulator
Magnetic coil
Thermal relay
Circuit breaker
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
Automatic voltage trip regulator
Main circuit breaker tripping system
No fuse breaker tripping system
Electrolyte in a lead-acid storage battery has water and _
Sulfuric acid
Alkaline
Tap water
Sulfur
What kind of electrical wiring configuration of a three-phase motor in which one end of each of the three phases is connected to the other phases internally, and the remaining end of each phase is then brought out externally and connected to the power line?
Wye configuration
Delta configuration
Dual-voltage configuration
Forward-reverse configuration
In using a fuse whose rating is higher than necessary will _
waste money because they are more expensive
reduce the possibility of fuse getting blown
increase the efficiency of the apparatus
endangers the apparatus it is supposed to protect
Which of the following safety device belongs to the main engine shutdown trip?
Camshaft LO low pressure
Exhaust gas temperature high
Overspeed
FO low pressure
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
Linear variable differential transformer type
Differential pressure level control type
Level control probe type
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
auto start circuit
start button
remote start circuit
sequential timer
There are two factors considered in classifying a voltage as "High Voltage". One is the possibility of causing a spark in air. What is the other one?
Voltage 900V and above
Less extensive with complex networks and connections
Danger of electric shock by contact or proximity
Magnitude of current flow is too large when large loads are connected
What form of power loss is the result of resistance in a distribution circuit heating of conductors?
line droop
R drop
hysteresis
line loss
To calculate the Volt Amperes (VA), what do you need to know?
voltage and current
resistance and impedance
ohms and resistance
impedance and conductance
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 solenoid actuated with spring return directional valve
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
Which of the following type of motors is used where uniform speed, regardless of load, is needed?
Shunt wound motor
Compound wound motor
Separately exciter motor
Series wound motor
The electro-pneumatic circuit layout follows the signal flow through the control chain from bottom to top. However, the electric circuit elements are numbered following the direction of signal flow from _
left to right
right to left
top to bottom
bottom to top
The conversion of throttle command voltage to the signal necessary to achieve the desired shaft, RPM is accomplished by _
ahead or astern function generator of the throttle power circuit
feedback resistor of the summing amplifier circuit
operational amplifiers in the auto rotation circuit
ahead or astern function generator of the throttle control circuit
Pneumatic directional valve symbols 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 lines
Working lines
Exhaust lines
Control lines
In a 5/2-way double solenoid directional valve, what does 5/2 mean?
5 ports, double solenoid
5 switching positions, 2 ports
5 ports with 2 exhaust connections
5 ports, 2 switching positions
Which of the following indicate the temperatures in AC generator?
Deep well thermometers
Standard thermometers
Pyrometer
Imbedded thermocouples
When choosing a battery for a particular application, major consideration should be given to the battery's _
amp-hour capacity
stability under charge
terminal polarity
ambient temperature rise
What alarm is initiated causing the feed water pump to stop, cutting water supply to the boiler drum, preventing the drum from excessive hydraulic pressure exerted by the feed water, which may explode the boiler drum or at least, weaken it?
Low atomizing steam pressure alarm
High water level alarm
High steam pressure alarm
High-high water level alarm
Which of the following definitions best describes sensitivity as a characteristic of controller action?
The ratio of the output in response to a specified change to the input which caused it
The variation of the manipulated variable of the controlled variable corresponding to the set point
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
What kind of directional valve whose function is to control the direction taken by the fluid flow with flow in both directions and to release the fluid displaced from the actuator to other control purposes?
One-way flow control valve
5/2-way directional control valve
4/2-way directional control valve
3/2-way solenoid actuated with spring return directional valve
Before an insulation test is carried out inside the group starter panel circuit board, the wirings leading to the sensitive circuits shall be _
removed
tested first
grounded
taken away
In an electro-hydraulic steering gear, any change in relative position between the synchronous receiver and the follow-up gear will result in _
closing of the six-way valve
the pump going to full stroke
driving the rams up against the stops
a corresponding slowing or increasing of the pumped flow rate
Most AC voltmeters are calibrated to read _
Root-mean-square voltage
Peak voltage
Peak-to-peak voltage
Average voltage
What type of valve is installed in series with the water level control valve between the feed water pump and boiler drum?
Butterfly valve
Check valve
Ball valve
Gate valve
Pneumatic directional valve symbols consist of either letter or the numbers 1, 2, 3, 4, and 5 as per DIN ISO 5599. What does number 1 represents?
Working line
Exhaust line
Control line
Air source connection
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 with clean air to detect a problem?
Lube oil differential pressure gauge
Fuel oil viscosity controller
Oil mist detector
Scavenging limit transmitter
Which of the following statements is correct concerning electrical wirings?
When passing through bulkheads, they should be fitted with watertight stuffing
Electric cable coverings should never be grounded
Electrical cables must be rigidly held in place by armored cable, or glued in place with non-metallic insulation
Electrical cables should be grounded in the bulkheads
What can be obtained in an open circuit if we use the instrument called merger tester?
Insulation efficiency
Maximum load
Current flaw
Resistance of wire
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
High ampere charging circuit
Normal charging circuit
Quick charging circuit
The efficiency of a Diesel engine is greatest at about 80% of maximum load. If a CPP is used, at which level, in general, the propeller efficiency is greatest?
High pitch and high rpm
High pitch and low rpm
Low pitch and low rpm
Low pitch and high rpm
MCB-type circuit breakers are called _
mechanical contact circuit breaker
molded-case circuit breaker
mounted-case circuit breaker
mono block-case circuit breaker
Capacitors are measured in _
Ohms
Farads
Volts
Watts
According to International Regulations, which of the following is true concerning portable electric cord and fixture wire aboard ship?
Splices or taps not permitted in cable runs longer than 30 feet
Solderless crimp-on splices with outside insulators are permitted
No splices or taps are permitted
Soldered splices with electrical taps are permitted
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 _
water level probe sensor
water level capacitance probe
water level transmitter
water gauge glass
When the voltage and the current in an AC circuit reach their peak valve at the same time, the power factor is _
infinity
lagging
unity
leading
A semi-conductor is a material with a _
high conductivity at low temperatures
conductivity lower than a normal insulator
conductivity higher than a normal conductor
conductivity higher than a normal isolator
On an engine throttle control system, the auxiliary control circuits are provided with devices to prevent excessive over travel of the pilot valve by the synchronous motor. These devices are called _
three times in a year proximity switches
overlap relays
overlap sensors
limit switches
Reducing the frequency in a capacitative circuit while holding voltage constant will realist in a _
decrease in total impedance
decrease in capacitative reactance
decrease in circuit current
increase in apparent power
Positive ions going to the negative electrode is called _
proton
anions
cations
electrons
External shunts are sometimes provided in ammeters to _
prevent damage from heat generated by the shunt
enable the construction of meter with a virtually unlimited range
increase meter sensitivity
permit shunts with larger resistances to be utilized
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 a hydrometer
test insulation values with a merger
ground the commutator, or slip rings and run it at half load for 12 hours
What element is placed inside switch boxes of deck machineries outside the engine worn to avoid short circuits?
Absorbent material
Sodium chloride
Carbon tetrachloride
Silica gel
A displacer level sensor uses a _
displacer that varies in density from top to bottom
displacer heavier than the liquid in the process vessel
displacer exactly in weight to the volume of the liquid it displaces
displacer lighter than the liquid in the process vessel
Some of the disadvantages of HV system on ships include usage of high-class insulation on conductors (generally 'F' class and above) and special witch gears required to prevent arcing. What is another disadvantage?
Using HV electric propulsion further increases engine room size, hence, lesser cargo space
Copper loss are increase when compared to LV system, as the current flow is more
Higher voltages have greater risk and hence require stringent safety procedures
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?
Variable torque/Variable HP
Constant torque/Variable HP
Constant HP/Variable torque
Constant HP/Constant torque
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 _
decreasing excitation
raising the generator engine speed
rotating brush alignment
lowering the generator engine speed
When compared to other component in an electronic circuit, the integrated circuit (IC) is _
smaller, more reliable and often less expensive
smaller, less reliable, and less expensive
larger, more reliable, and less expensive
smaller, more reliable, and generally expensive
The total resistance of a parallel circuit is always _
unequal to the sum of the individual branch resistance
smaller than that of the branch with the lowest resistance
larger than that of the branch with greatest resistance
equal to the sum of the individual branch resistance
In paralleling of two generators, what does it indicate if the synchronizing lamps remain lighted as the synchroscope pointer approaches the zero degree position?
two generators are in parallel
the flow of power is in reverse direction
the voltage reading of incoming generator is lower than 440 volts
two generators are in phase
If the main propulsion diesel governor works irregularly with a jerking motion, a possible cause can be _
95 degrees Celsius
A constant quantity regulating valve
A sticking fuel control linkage
Excessive pressure in the seawater feed heater
How does a puncture valve function in stopping the main engine or during shutdown?
It reduces the high pressure of the fuel oil by connecting the HP side to the pump body, thereby stopping the injection of the fuel
It introduces HP compressed air to the reversing cylinder t apply brake on the engine
It lifts the fuel cam follower from the cam nose so that no fuel pumping can occur
It cuts-off the HP fuel by closing the inlet ball valve using compressed air from the stop directional valve
Which of the following statements correctly applies to transistors?
The collector separates the emitter and base
The emitter separates the base and collector
The three terminals are called the emitter, base, and collector
NDN and PNP are the two basic types of transistors
On tank vessels with an electrically-driven capstan, the motor should be tested periodically with its _
armature capacitance
insulation resistance
capacitance
eddy currents
The purpose of the commutator and brushes on a DC generator is to _
transfer generated direct current voltage from the armature to the line
convert the alternating voltage generated within the armature to a direct voltage
provide a sliding method to excite the field
reduce sparking between the armature and the carbon brushes
The purpose of the commutator and brushes on a DC generator is to _
transfer generated direct current voltage from the armature to the line
convert the alternating voltage generated within the armature to a direct voltage
provide a sliding method to excite the field
reduce sparking between the armature and the carbon brushes
The power supply of a merger is obtained from _
batteries
a magneto
any 115 volt AC circuit
any 115 volt DC circuit
What alarm prevents the accumulation of fuel into the furnace which may become the source of explosion if not properly purged? This alarm is overridden during starting up/firing up of the boiler
Flame failure alarm
High water level alarm
Low combustion air pressure alarm
Low atomizing steam pressure alarm
In which of the following mode does a (JFET) operates?
Depletion
Shrinking
Contraction
Expansion
Movement of electrons due to electromagnetism is called _
Thermal conduction
Magnetic effect
Inductive effect
Induction
What is the ratio between the insulation resistance (IR) valve measured after the application of the test voltage continuously for 10 minutes to the IR value measured after 1 minute of application?
Polarization index or PI value
Insulation Resistance or IR value
Power Loss or I2R value
Grounding Index or GI
How is the operator ensured that he is not in contact with any unearthed conductor before insulation resistance (IR) measurement of a HV system?
Disconnect the power supply to the HV equipment by opening circuit breaker and opening isolator
Connect the insulation resistance (IR) tester to the conductor with safety earth connection ON
After connecting insulation resistance (IR) tester to the circuit, safety earth is to be disconnected
Confirm that all the phases are dead using an approved live line
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 pilot air
By helical springs
By air springs
By air pistons
Which of the following statements represents the FIRST step in seating new brushes on slip rings?
apply seating compound around the slip rings and slide it back and forth between the brushes and the slip rings
apply seating compound under the brushes and run at no load for 2 hours
press the brushes against the slip ring with a wood block
What does oil mist detector use to measure small increases in oil mist density?
Strain gauge
Vibration cell
Photoelectric cell
Rectifier diode
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 of copper
lower than that of copper
reached when the conductor it protecting becomes 'white hot'
equal to that of copper
Which of the following statements is correct for electric cables penetrating decks and bulkheads?
Bushings should be used when passing through deck machinery
Stuffing tubes should be used
Arrangements must be made to ensure fire resistance
Bushings should be used when passing through deck beams
The loop of wire that rotates through and cut the magnetic field in a generator is called _
poles
slip ring
armature
carbon brushes
While starting a main propulsion synchronous motor, the ammeter pegs out at maximum and then returns to the proper value after synchronization. What does this indicate?
Field windings are grounded
Motor has started properly
Slip rings are dirty
Power transmission cables are grounded
Which of the method listed is sued to maintain equal load sharing between two compound wound DC generators operating in parallel?
The series field of both generators are connected in series
The series field of both generators are connected in parallel
The shunt field rheostats are interconnected
The shunt field are interconnected
What is fitted in the main air line immediately before the air start valve of a large Diesel engine to restrict the risk of a flame in the cylinder propagating back to the main air start manifold, by dissipating the heat energy in the flame?
Spark arrester
Flame arrestor
Ignition circular disc
Flame retardant
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?
Double-acting cylinders
Hydraulic motors
Rotary pumps
Single-acting cylinders
Current measuring instrument must always be connected in_
series-parallel with a circuit
delta with the shunt
parallel with a circuit
series with a circuit
The difference between the synchronous speed of an induction machine and its operating speed (slip) may be correctly expressed as _
a decimal fraction of synchronous speed
directly in revolutions per minute
a series wound motor
a percent of synchronous speed
What electric device that must be fitted in all generator circuit breakers?
Overcurrent relay
Frequency meter
Step-up transformer
Step-down transformer
All transformers have the same operating principles and characteristics, and every transformer has a primary winding and _
main windings
secondary winding
core winding
auxiliary winding
To ensure boiler is operated at high efficiency, what should be the best feed water temperature setting of the temperature controller?
80-85 degree Celsius
90-95 degree Celsius
60-65 degree Celsius
55-60 degree Celsius
Each hydraulic system must be fitted with a pressure relief valve downstream of the pump to prevent accidents and damage caused by excessive pressures. Spring loaded relief valves are used to adjust the working pressures and limit the operating pressures are also employed as safety valves. What kind of relief valves are used whenever large volumes of hydraulic oils are involved?
Solenoid controlled pressure relief valves
Counter-balanced valves
One-way flow control relief valves
Pilot controlled pressure relief valves
What is the meaning of FRL installed in most pneumatic energy supplies?
Fiber Reinforced Lining
Full Reservoir Level
Filter, Regulator, Lubricator
Fire Resistance Level
What determines the power factor of an electric distribution system being supplied by a single AC generator?
By components of the connected load
By prime mover speed
By output frequency
By generator's rated voltage
What is the greatest single cause of electrical failure?
overcurrent
breakdown of insulation
breakdown of conduction
high voltage
In general, Zener diodes can dissipate more power of its leads are _
elongated
shortened
prolonged
extended
The automatic combustion control systems for some auxiliary boilers are designed to cycle burners on in response to _
fuel return pressure
low fuel pressure
low steam pressure
furnace air pressure
In a boiler under auto-firing operation, what is the next sequence after the completion of the pre-during operation?
Fuel is supplied to the pilot burner
Post-purging operation is initiated
Power is supplied to the electrodes of the pilot burner
Fuel is supplied to the main burner
