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Worksheets1.4 MSAP 2024 MCQ Template - ELECTRICAL, ELECTRONIC & CONTROL E
Total questions: 250
Worksheet time: 2hrs 5mins
Name
Class
Date
1.
Prior to starting an AC generator prime mover,the voltage regulator cut out switch should be placed in the_____.
a)
transfer position
b)
raise voltage position
c)
bus neutral position
d)
manual position
2.
Temporary repairs to an open DC propulsion armature coil can be made by __________.
a)
connecting the coil ends directly to a pair of negative brushes
b)
disconnecting coil ends, insulating each, and short circuiting the two commutator bars
c)
grounding the coil ends and short circuiting the commutator bar
d)
removing the sparking brushes
3.
The charge of an alkaline battery can be determined with_____________.
a)
an ammeter
b)
a voltmeter
c)
a hygrometer
d)
a hydrometer
4.
The direction of rotation of a DC propulsion motor can be changed by reversing the __________.
a)
brush holder position
b)
polarity of the field poles
c)
brush staggered order
d)
motor interpole connections
5.
The energy consumed by an AC motor, as strictly reactive power, is __________.
a)
used to do mechanical work
b)
used to establish the magnetic field of the motor
c)
lost as heat generated by bearing friction
d)
lost in doing work to turn the motor itself
6.
The instruments installed in a main switchboard that are very useful in synchronizing generator together are ____________? I - Synchroscope Lamps II - Governor Control III - Induction Motor
a)
I and II
b)
II and III
c)
I and III
d)
I, II, and III
7.
The most common of excitation for synchronous motor is a/an:
a)
AC supply
b)
Step-up transformer
c)
DC supply
d)
Poor contact of brushes
8.
The parts of a transformer to which an AC voltage is applied is/are _______________. I - Secondary Wiring II - Primary Winding III - Iron Core
a)
I only
b)
II only
c)
I and III
d)
II and III
9.
The rate at which heat is produced in a direct current circuit is equal to __________.
a)
P divided by R
b)
I squared times R
c)
E divided by I
d)
I times R divided by T
10.
The solenoid valve is controlled by:
a)
the thermal switch operated by the icebox temperature
b)
the amount of liquid in the system
c)
the temperature in the condenser
d)
the amount of gas in the system
11.
The true power indicated by a wattmeter depends on the current flow through the load, the magnitude of the potential across the load, and the __________.
a)
power factor of the load
b)
angle of coil displacement
c)
inertia of the movable coil
d)
high resistance from the load
12.
Thermal strip heaters are provided in DC main propulsion motors to __________.
a)
prevent moisture buildup in windings
b)
maintain a relatively constant temperature in the motor enclosure
c)
prevent the rotor from warping
d)
provide an additional means of starting resistance
13.
Three wire DC generators can oncorporate an unbalance of_____________.
a)
10%
b)
25%
c)
5%
d)
50%
14.
Two dissimilar metal strips commonly bonded together into a single unit. This unit change its shape when subjected to heat ______.
a)
Bimetallic strip
b)
Coupled strip
c)
Heat strip
d)
Thermocouple
15.
What current is required to light two 75 watt lamps and one 40 watt lamp when connected in parallel to a 120 volt power source?
a)
0.161 amperes
b)
0.631 amperes
c)
1.583 amperes
d)
6.199 amperes
16.
What is the approximate voltage per cell produced by the nickel-iron (Edison) battery?
a)
0.85 volts
b)
1.35 volts
c)
2.20 volts
d)
6.05 volts
17.
What is the unit of measured being on electric wires and cables?
a)
Square inch
b)
Cubic milimeters
c)
Circular miles
d)
Length in feet
18.
What kind of overload relay that is being actuated by an electromagnetic coil?
a)
Magnetic
b)
Thermal
c)
Current
d)
Voltage
19.
What will happen to the alternator frequency if the load is removed from a turbo charger whose governor a 3 percent speed drop?
a)
it will remain unchanged
b)
it will decrease approximately 3 percent
c)
it will become variable
d)
it will increase
20.
When paralleling two AC generators, the frequency (cycles) of the incoming generator, just prior to closing the circuit breaker, should be __________.
a)
slightly less than the frequency of the generator on the line
b)
the same as the frequency of the generator on the line
c)
slightly more than the frequency of the generator on the line
d)
all of the above
21.
When troubleshooting a console circuit card suspected of being faulty, the last step would be to __________.
a)
check the fuses and voltage levels of all power supplies in the console
b)
clean dust and debris from the card and burnish the sliding connections
c)
make sure all connections are tight including wire wrappings and push-on types
d)
substitute a new or repaired spare card and check the operation of the circuit
22.
Which of the following components are used to assemble a fluorescent lighting system?
a)
Lamp
b)
Starter
c)
Ballast
d)
All of the above
23.
Which of the following procedures should be used to determine the load of a three-phase, delta wound, AC generator?
a)
Multiply the amperage in one phase by three.
b)
Divide the total amperage in all phases by three.
c)
Multiply the amperage in one phase by the square root of three.
d)
Divide the total amperage in all phases by the square root of three.
24.
Which of the formulas listed is correct for determining power?
a)
P = (E)(E)/R
b)
P = (I)(R)(R)
c)
P = (I)(I)/R
d)
P = E/R
25.
Which type of generator will most likely lose its voltage over a range of 60% to 1255 of full load?
a)
Under compounded
b)
Flat - compounded
c)
Over compounded
d)
Combination - compounded
26.
A circuit in which a fuse has blown would be considered as a__________________.
a)
short circuit
b)
open circuit
c)
borded circuit
d)
ground circuit
27.
A fully charged battery reads from:
a)
1.280 to 1.300
b)
1.025 to 1.075
c)
1.050 to 1.350
d)
1.200 to 1.500
28.
A megohmmeter is connected to each end of an individual motor winding. A low ohm reading indicates __________.
a)
an open coil
b)
a loose coil
c)
good continuity
d)
a dirty coil
29.
A short circuit may be measured by_____________.
a)
megger
b)
voltmeter
c)
dynamometer
d)
ammeter and ohmeter
30.
A voltmeter is connected in a circuit in_____________.
a)
relay
b)
series
c)
series parallel
d)
parallel
31.
An AC circuit has capacitance arranged in series. If the line voltage remains constant, the capacitive reactance value can be varied by changing the __________.
a)
line frequency
b)
resistance
c)
number of commutating poles
d)
number of interpoles
32.
An open coil can be detected by_______________.
a)
high resistance
b)
low resistance
c)
normal operation
d)
needs adjustment
33.
Before you remove a small capacitor which is connected to a de-energized circuit, or which is disconnected entirely, you should___.
a)
be equipped with an insulated fuse puller
b)
tag it with a de-energized tag
c)
gentle tap it with a screwdriver
d)
short circuit the terminals to make sure that the capacitor is discharged
34.
Conducting materials such as copper, aluminum and tungsten____________.
a)
increase in resistance with in increased temperature
b)
increase in resistance with decreased temperature
c)
decrease in resistance with in increased temperature
d)
increase in conductance with increased temperature
35.
Electrical leads and insulation on a motor should be painted with:
a)
insulating varnish
b)
heat-resisting aluminum
c)
heat-resisting enamel
d)
insulating white lead
36.
How is lead-acid cell tested?
a)
hydrometer
b)
hygrometer
c)
hogometer
d)
megometer
37.
If field excitation is suddenly lost to an alternator operating in parallel, that alternator will __________.
a)
supply excessive current to the bus
b)
operate at the same load, but with reduced voltage
c)
lose its load and tend to over speed
d)
become overloaded and slow down
38.
In a basic induction motor, rotor currents are circulated in the rotor by __________.
a)
a bridge rectifier
b)
an armature and brushes
c)
inductive reaction of the rotating stator field
d)
external variable resistors
39.
In an induction motor, the current are citculated in the rotor by the:
a)
slip rings and brushes
b)
an armature and brushes
c)
inductive action of the rotating stator flux
d)
internal variables resistors
40.
It is a device that prints out a permanent record of a machinery operationg conditions in an automated vessel.
a)
Data recorder
b)
Computer
c)
Analyzer
d)
Log adjuster
41.
It is an electric switch whre a circuit is connected to one part of another circuit in one position of a switch and to another part of the circuit in the other position.
a)
Multi-pole
b)
Double throw
c)
Double pole
d)
Single throw
42.
It is the reason why there is visual spark in the commutator during operation of a D. C. motor.
a)
Worn out bearing
b)
Worn out carbon brush
c)
Misaligned slip ring
d)
Overloading of water
43.
Motor field can be tested by a/an____________.
a)
voltmeter
b)
megger
c)
wattmeter
d)
ammeter
44.
Prior to starting an AC generator prime mover, the voltage regulator selector switch should be placed in the __________.
a)
manual position
b)
bus neutral position
c)
raise voltage position
d)
transfer position
45.
Temporary repairs to an open DC propulsion armature coil can be made by __________.
a)
connecting the coil ends directly to a pair of negative brushes
b)
disconnecting coil ends, insulating each, and short circuiting the two commutator bars
c)
grounding the coil ends and short circuiting the commutator bar
d)
removing the sparking brushes
46.
The charge of an alkaline battery can be determined with_____________.
a)
an ammeter
b)
a voltmeter
c)
a hygrometer
d)
a hydrometer
47.
The direction of rotation of a DC propulsion motor can be changed by reversing the __________.
a)
brush holder position
b)
polarity of the field poles
c)
brush staggered order
d)
motor interpole connections
48.
The ends of the armature loop are connected & also rotate to the armature itself in a DC generator is _______.
a)
The carbon brushes
b)
The exciter
c)
The slip rings
d)
The rectifier
49.
The instrument used to indicate the level of a fluid in a tank is called a __________.
a)
fluid meter
b)
calorimeter
c)
viscosimeter
d)
pneumercator
50.
The most common method of producing electricity for electrical power is by:
a)
chemical action
b)
magnetism
c)
electrolysis
d)
acid solution
51.
The parts of a generator where the end of an armature coils one connected that also rotate with the armature is called _____________.
a)
Carbon brushes
b)
Slip rings
c)
South poles
d)
North poles
52.
The rate at which charges move through a material can be measured by the use of an electrical instrument called_____________.
a)
Voltmeter
b)
Ohmmeter
c)
Wattmeter
d)
Ammeter
53.
The solenoid valve can be types as a:
a)
thermal valve
b)
bellow valve
c)
bimetal valve
d)
magnetic stop valve
54.
The total voltage of a series circuit is the __________.
a)
sum of the individual voltage drops
b)
total resistance divided by the total current
c)
sum of the individual currents multiplied by the number of resistors
d)
total current divided by the total resistance
55.
There are the elements that contain both series and parallel combinations to form the total opposition called impedence to the flow of current in an A. C. electric circuit.
a)
I & II
b)
II & III
c)
I & III
d)
I, II, & III
56.
Three wire DC generators can oncorporate an unbalance of_____________.
a)
10%
b)
25%
c)
5%
d)
50%
57.
Two DC drive propulsion motors provide input to a single output reduction gear. Upon relieving the watch, you notice that the starboard motor indicators show zero current compared to normal voltage and current indicated on the port motor. The problem wi
a)
a tripped reverse power relay
b)
a tripped reverse current relay
c)
overheating of the load inverter
d)
a tripped variable frequency converter
58.
What could be an application of a silicon controlled rectifier?
a)
To provide DC power for a main propulsion motor
b)
For use as a voltage reference diode
c)
For sensing flame in an automated burner
d)
Second electromagnet
59.
What is the approximate discharge voltage produced by one wet cell of a nickel-cadmium battery?
a)
1.25 volts
b)
1.5 volts
c)
2.2 volts
d)
6.0 volts
60.
What is the unit of measured being on electric wires and cables?
a)
Square inch
b)
Cubic milimeters
c)
Circular miles
d)
Length in feet
61.
What kind of overload relay that is being actuated by an electromagnetic coil?
a)
Magnetic
b)
Thermal
c)
Current
d)
Voltage
62.
What will happen to the alternator frequency if the load is removed from a turbo charger whose governor a 3 percent speed drop?
a)
it will remain unchanged
b)
it will decrease approximately 3 percent
c)
it will become variable
d)
it will increase
63.
When paralleled, AC generators must have the same __________.
a)
frequency
b)
number of phases
c)
phase rotation
d)
all of the above
64.
When troubleshooting a console circuit card suspected of being faulty, first check operating voltages, clean the card and then __________.
a)
make sure wired connections and push-on connectors are tight
b)
test each resistor and capacitor on the card with an ohmmeter
c)
check the continuity of all printed circuit traces with an ohmmeter
d)
measure the gain of each transistor or integrated circuit
65.
Which of the following components are used to assemble a fluorescent lighting system?
a)
Lamp
b)
Starter
c)
Ballast
d)
All of the above
66.
Which of the following procedures represents the best method to prevent the freezing of batteries continuously exposed to low temperatures?
a)
The battery caps should be removed.
b)
The battery cap vents should be sealed.
c)
The battery should be kept in a fully charged condition.
d)
The battery should be disconnected from its charging source.
67.
Which of the formulas listed is correct for determining power?
a)
P = (E)(E)/R
b)
P = (I)(R)(R)
c)
P = (I)(I)/R
d)
P = E/R
68.
Which type of generator will most likely lose its voltage over a range of 60% to 125% of full load?
a)
Under compounded
b)
Flat-compounded
c)
over compounded
d)
combination compounded
69.
A circuit in which a fuse has blown would be considered as a__________________.
a)
short circuit
b)
open circuit
c)
boarded circuit
d)
ground circuit
70.
A full-wave rectifier has one diode burned out in an open condition, what will be the output characteristic of the device?
a)
Zero
b)
Half-wave rectified
c)
Full-wave rectified
d)
Equal to the AC input
71.
A megohmmeter is being used to test insulation resistance current leakage along the surface o the insulation is indicated by the megohmeter's pointer _______.
a)
Kicking slightly downscale as voltage is applied
b)
Approaching laterally as current flow
c)
Approaching momentarily as resistance is applied
d)
At neutral position as inductive is applied
72.
A short circuit may be measured by_____________.
a)
megger
b)
voltmeter
c)
dynamometer
d)
ammeter and ohmeter
73.
A voltmeter is connected in a circuit in_____________.
a)
relay
b)
series
c)
series parallel
d)
parallel
74.
An AC circuit has a capacitive reactance of 30 ohms in addition to an inductive reactance of 40 ohms connected in series. What is the reactance of the circuit?
a)
8.37 ohms
b)
10.00 ohms
c)
50.00 ohms
d)
70.00 ohms
75.
An open coil can be detected by_______________.
a)
high resistance
b)
low resistance
c)
normal operation
d)
needs adjustment
76.
Before working on an electric cargo winch master switch or controller, you should __________.
a)
spray the gasket surface with a solvent
b)
drain condensate from the box
c)
open the circuit breaker in the power supply and tag-out
d)
heat the switch box to remove any moisture
77.
Conducting materials such as copper, aluminum and tungsten____________.
a)
increase in resistance with in increased temperature
b)
increase in resistance with decreased temperature
c)
decrease in resistance with in increased temperature
d)
increase in conductance with increased temperature
78.
Electrical leads and insulation on a motor should be painted with __________.
a)
heat-resisting acrylic
b)
heat-resisting aluminum
c)
insulating varnish
d)
insulating white lead
79.
How is DC output obtained from a brushless exciter?
a)
Directly from the commutator by induction
b)
By the use of ship rings mounted on the armature
c)
By the use of semiconductor rectifier mounted on ht exciter armature
d)
By the use of semiconductor rectifier mounted on the stator
80.
If field excitation is suddenly lost to an alternator operating in parallel, that alternator will __________.
a)
supply excessive current to the bus
b)
operate at the same load, but with reduced voltage
c)
lose its load and tend to overspeed
d)
become overloaded and slow down
81.
In a basic induction motor, rotor currents are circulated in the rotor by __________.
a)
a bridge rectifier
b)
an armature and brushes
c)
inductive reaction of the rotating stator field
d)
external variable resistors
82.
In an induction motor, rotor currents are circulated in the rotor by:
a)
slip rings and brushes
b)
armature and brushes
c)
inductive action of the rotating stator flux
d)
external variable resistors
83.
It is a device that is being installed in an A. C. main switcboard but cannot be found in a D. C. main switcboard.
a)
Frequency meter
b)
Voltage regulation
c)
Governor control
d)
Voltmeter
84.
It is an electric switch where a circuit is connected to one part of another circuit in one position of a switch and to another part of the circuit in the other position.
a)
Multi pole
b)
Double throw
c)
Double pole
d)
Single throw
85.
It is the reason why the entire core and coil assembly of transformer are dipped in an insulating varnish and baked in solid mass.
a)
avoid vibration and wear
b)
avoid loss of current
c)
obtain more efficient voltage regulation
d)
obtain more efficient insulation
86.
Motor field can be tested by a/an____________.
a)
Voltmeter
b)
megger
c)
wattmeter
d)
ammeter
87.
Prior to starting an AC generator prime mover, the voltage regulator selector switch should be placed in the __________.
a)
manual position
b)
bus neutral position
c)
raise voltage position
d)
transfer position
88.
Temperatures in AC generator are indicated by:
a)
Pyrometer
b)
Deep well thermometers
c)
Imbedded thermocouples
d)
Standard thermometers
89.
The charge of a lead-acid battery is normally checked with a/an __________.
a)
manometer
b)
hydrometer
c)
pneumercator
d)
ohmmeter
90.
The direction of propeller shaft rotation in a turbo-electric AC synchronous propulsion drive motor is changed by reversing the __________.
a)
polarity of the propulsion motor
b)
polarity of the propulsion generator
c)
phase sequence of power to the motor
d)
phase sequence of power to the generator
91.
The end current that will flow in a 9 ampere current that passes in a resistor of 20 ohms and 40 ohms connected in parallel will be_____________.
a)
3
b)
6
c)
9
d)
12
92.
The instrument or device that measure the content of a big tank are ______________ . I - Sounding Tape II - Float III - Pneumercator
a)
I and II
b)
I and III
c)
II and I
d)
I, II, and III
93.
The most common method of producing electricity for electric power used is_____________.
a)
electrolysis
b)
magnetism
c)
Chemical action
d)
Heat transfer
94.
The parts of a generator where the end of an armature coils one connected that also rotate with the armature is called _____________.
a)
Carbon brushes
b)
Slip rings
c)
South poles
d)
North poles
95.
The range of values through which the input can be varied without initiating an output response is known as __________.
a)
deviation
b)
offset
c)
sensitivity
d)
dead band
96.
The small variable shunt connected across the series field coils to permit adjustment of the degree of compounding is called_____________.
a)
Diverter
b)
Divider
c)
Resistor
d)
Rheostat
97.
The total voltage of a series circuit is the __________.
a)
sum of the individual voltage drops
b)
total resistance divided by the total current
c)
sum of the individual currents multiplied by the number of resistors
d)
total current divided by the total resistance
98.
There are many lights onboard. Where are the emergency lights mostly located?
a)
Bridge deck
b)
Steering room
c)
Mast hauses
d)
Passage ways
99.
Three wire DC generators can incorporate an unbalance of_____________.
a)
10%
b)
25%
c)
5%
d)
50%
100.
Two DC drive propulsion motors provide input to a single output reduction gear. Upon relieving the watch, you notice that the starboard motor indicators show reduced voltage and zero current compared to normal voltage and current indicated on the port mo
a)
a tripped reverse power relay
b)
a tripped reverse current relay
c)
overheating of the load inverter
d)
a tripped variable frequency converter
101.
What could be an application for a silicon controlled rectifier?
a)
to provide power for a main ropulsion motor
b)
for use as a voltage reference diode
c)
for sensing flame is an automated burner
d)
to eliminate power supply hum
102.
What is the approximate discharge voltage produced by one wet cell of a nickel-cadmium battery?
a)
1.25 volts
b)
1.5 volts
c)
2.2 volts
d)
6.0 volts
103.
What is the unit of measured being on electric wires and cables?
a)
Square inch
b)
Cubic milimeters
c)
Circular lines
d)
Length in feet
104.
What kind of overload relay that can well protect a motor against high ambient temperature or inadequate ventilation that can also be adjusted either manual or automatic resetting?
a)
Electronic
b)
Thyristor
c)
Magnetic
d)
Thermal
105.
What will happen to the alternator frequency if the load is removed from a turbo charger whose governor a 3 percent speed drop?
a)
it will remain unchanged
b)
it will decrease approximately 3 percent
c)
it will become variable
d)
it will increase
106.
When paralleled, AC generators must have the same __________.
a)
frequency
b)
number of phases
c)
phase rotation
d)
all of the above
107.
When troubleshooting a console circuit card suspected of being faulty, first check operating voltages, clean the card and then __________.
a)
make sure wired connections and push-on connectors are tight
b)
test each resistor and capacitor on the card with an ohmmeter
c)
check the continuity of all printed circuit traces with an ohmmeter
d)
measure the gain of each transistor or integrated circuit
108.
Which of the following components are use to assemble a fluorescent lightning system?
a)
lamp
b)
starter
c)
ballast
d)
all of these choices
109.
Which of the following procedures represents the best method to prevent the freezing of batteries continuously exposed to low temperatures?
a)
The battery caps should be removed.
b)
The battery cap vents should be sealed.
c)
The battery should be kept in a fully charged condition.
d)
The battery should be disconnected from its charging source.
110.
Which of the following would you not normally find on a DC generator?
a)
Binding wires
b)
Slip rings
c)
Brush holder
d)
Air gap
111.
Which type of generator will most likely lose its voltage over a range of 60% to 125% of full load?
a)
Under compounded
b)
Flat-compounded
c)
over compounded
d)
combination compounded
112.
A circuit in which a fuse has blown would be considered as a__________________.
a)
short circuit
b)
open circuit
c)
boarded circuit
d)
grounded circuit
113.
A full-wave rectifier has one diode burned out in an open condition, what will be the output characteristic of the device?
a)
Zero
b)
Half-wave rectified
c)
Full-wave rectified
d)
Equal to the AC input
114.
A megohmmeter can be used to test for __________.
a)
an open field coil
b)
a shorted field pole
c)
undercut mica
d)
reversed polarity
115.
A short circuit in the armature of a DC motor will cause the motor to __________.
a)
run fast
b)
hum when energized
c)
spark at the brushes
d)
fail to start
116.
A voltmeter is connected in a circuit in_____________.
a)
relay
b)
series
c)
series parallel
d)
parallel
117.
An AC circuit has a capacitive reactance of 30 ohms in addition to an inductive reactance of 40 ohms connected in series. What is the reactance of the circuit?
a)
8.37 ohms
b)
10.00 ohms
c)
50.00 ohms
d)
70.00 ohms
118.
An open armature connection in a DC propulsion motor could be caused by __________.
a)
low-load operation
b)
clogged ventilation ducts
c)
sparking at the brushes
d)
a grounded shunt field coil
119.
Before working on an electric cargo winch master switch or controller, you should __________.
a)
spray the gasket surface with a solvent
b)
drain condensate from the box
c)
open the circuit breaker in the power supply and tag-out
d)
heat the switch box to remove any moisture
120.
Conducting materials such as copper, aluminum and tungsten____________.
a)
increase in resistance with in increased temperature
b)
increase in resistance with decreased temperature
c)
decrease in resistance with in increased temperature
d)
increase in conductance with increased temperature
121.
Electrical leads and insulation on a motor should be painted with __________.
a)
heat-resisting acrylic
b)
heat-resisting aluminum
c)
insulating varnish
d)
insulating white lead
122.
How is a wattmeter electrically connected in a circuit?
a)
In series
b)
In parallel
c)
In series-parallel
d)
Inductively
123.
If field excitation is lost to an alternator operating in parallel with others, that alternators will_______________.
a)
reverse direction of rotation and over speed
b)
continue to operate at no load
c)
lose of its load and over speed
d)
become overloaded and slow down
124.
In a 60 Hz AC system, the current will pass through one complete cycle in __________.
a)
60 seconds
b)
6 seconds
c)
1 second
d)
.016 of a second
125.
In an induction motor with a cage rotor, the full load stator current is approximately_________times the running current.
a)
two
b)
three
c)
five
d)
nine
126.
It is a device that is being installed in an A. C. main switcboard but cannot be found in a D. C. main switcboard.
a)
Frequency meter
b)
Voltage regulation
c)
Governor control
d)
Voltmeter
127.
It is an electric switch where a circuit is connected to one part of another circuit in one position of a switch and to another part of the circuit in the other position.
a)
Multi pole
b)
Double throw
c)
Double pole
d)
Single throw
128.
It is the reason why the content of a big tank can be measure by the use of a pneumercator.
a)
Volume
b)
Pressure
c)
Weight
d)
Depth
129.
Motor efficiency can be determined by which of the following formulas?
a)
hp x 746 / watts input
b)
hp x 746 /VA
c)
hp x 746 / KVA input
d)
hp x 746
130.
Prior to performing any internal maintenance on a large DC main propulsion motor, precautions should be taken to __________.
a)
de-energize and lock out thermal heater circuits and any other auxiliary circuits located inside the motor housing
b)
tag and lock out the motors main circuit breaker
c)
engage shaft brake to prevent the rotor from accidentally turning
d)
All of the above
131.
T locate a grounded stator coil, you could use a/an____.
a)
ammeter
b)
ground detection lamp
c)
magnets
d)
megger
132.
The charge of a lead-acid battery is checked with a/an __________.
a)
manometer
b)
hydrometer
c)
voltmeter
d)
ohmmeter
133.
The direction of propeller shaft rotation in a turbo-electric AC synchronous propulsion drive motor is changed by reversing the __________.
a)
polarity of the propulsion motor
b)
polarity of the propulsion generator
c)
phase sequence of power to the motor
d)
phase sequence of power to the generator
134.
The end current that will flow in a 9 ampere current that passes in a resistor of 20 ohms and 40 ohms connected in parallel will be_____________.
a)
3
b)
6
c)
9
d)
12
135.
The instrument installed in a main switchboard that very necessary in synchronizing generators together are_____________.
a)
I & II
b)
II & III
c)
I & III
d)
I, II, & III
136.
The most common method of producing electricity for electric power used is_____________.
a)
electrolysis
b)
magnetism
c)
Chemical action
d)
Heat transfer
137.
The parts of a generator where the end of an armature coils one connected that also rotate with the armature is called _____________.
a)
Carbon brushes
b)
Slip rings
c)
South poles
d)
North poles
138.
The range of values around a setpoint of a measured variable where "no action" occurs in an automatic flow controller is called:
a)
deviation
b)
error
c)
deadband
d)
bias
139.
The small variable shunt connected across the series field coils to permit adjustment of the degree of compounding is called_____________.
a)
Diverter
b)
Divider
c)
Resistor
d)
Rheostat
140.
The total voltage induced into the secondary windings of a transformer is determined mainly by the ratio of the number of turns in primary to the number of turns in the secondary and by the ________.
a)
amount of voltage applied to the primary windings
b)
amount of current applied to the primary windings
c)
amount of resistance applied to the primary windings
d)
length of wire in the primary windings
141.
There are many causes of current leaks through the frame of electric motor that add to the break down of the insulation. What are the possible causes? I - High temperature II - Motor overloading III - High air moisture content
a)
I and II
b)
I and III
c)
II and III
d)
I, II, and III
142.
Three wire DC generators can incorporate an unbalance of_____________.
a)
10%
b)
25%
c)
5%
d)
50%
143.
Two DC drive propulsion motors provide input to a single output reduction gear. Upon relieving the watch, you notice that the starboard motor indicators show reduced voltage and zero current compared to normal voltage and current indicated on the port mo
a)
a tripped reverse power relay
b)
a tripped reverse current relay
c)
overheating of the load inverter
d)
a tripped variable frquency converter
144.
What controls or prevents the action of the starting lever of the main engine to be moved in a direction contrary to the telegraph demand in an automated vessel?
a)
Engine governor
b)
Master Valve
c)
Interlock Circuit
d)
Blocking Device
145.
What is the approximate discharge voltage produced by one cell of a wet type nickel-cadmium battery?
a)
1.25 volts
b)
1.5 volts
c)
2.2 volts
d)
6.0 volts
146.
What is the true concerning single parallel resistance circuits?
a)
the total current flow equals the reciprocal of the sum individual currents
b)
the total resistance equals the sum of the individual resistance
c)
the total current flow equals the sum of the individual currents
d)
the total voltage equals the sum of the individual voltages
147.
What kind of overload relay that can well protect a motor against high ambient temperature or inadequate ventilation that can also be adjusted either manual or automatic resetting?
a)
Electronic
b)
Thyristor
c)
Magnetic
d)
Thermal
148.
What will happen to the alternator frequency if the load is removed from a turbo charger whose governor a 3 percent speed drop?
a)
it will remain unchanged
b)
it will decrease approximately 3 percent
c)
it will become variable
d)
it will increase
149.
When operating an AC generator on a 3-phase 4-wire system, the neutral wire__________.
a)
maintains equal current in each phase
b)
maintain equal power in each phase
c)
maintains equal voltage in each phase
d)
has no current flow when the loads are unbalanced
150.
When troubleshooting a console circuit card suspected of being faulty, first check for proper voltages to the card and then __________.
a)
test transistors or integrated circuits for gain and compare with manufacturer's specifications
b)
blow any accumulated dust from the card with at least 30 psi air from the ship's service air system
c)
pull the card, clean the sliding connections with a pencil eraser, and remove accumulated dust
d)
de-energize the card and check the printed circuit traces for continuity with an ohmmeter
151.
Which of the following characteristics is most critical in determining the size of cable to be used in a particular circuit.
a)
voltage rating
b)
current rating
c)
inductance per unit length
d)
weight per unit length
152.
Which of the following problems will occur if the internal drain at either end of a hydraulic, two-way, spool-type directional control valve cylinder were to become plugged?
a)
The reservoir would become vapor bound.
b)
The valve would be placed in hydraulic lock.
c)
The spring loaded relief ports would open.
d)
The buffering chambers would be unable to function.
153.
Which of the following would you not normally find on a DC generator?
a)
Binding wires
b)
Slip rings
c)
Brush holder
d)
Air gap
154.
Which type of flux should be used when soldering wire connection?
a)
rosin flux
b)
solid flux
c)
acid flux
d)
silver flux
155.
A circuit in which a fuse has blown would be considered as a__________________.
a)
short circuit
b)
open circuit
c)
borded circuit
d)
ground circuit
156.
A fuel oil tank pneumercator will give an inaccurate reading if the __________.
a)
pneumercator is recharged with the air supply open
b)
pneumercator balance chamber bleed orifice is blocked by the oil being measured
c)
pressure in the system is allowed to equalize
d)
operating cock is placed in the 'vent' position when the system is not in use
157.
A megohmmeter can be used to test for __________.
a)
an open field coil
b)
a shorted field pole
c)
undercut mica
d)
reversed polarity
158.
A short circuit in the armature of a DC motor will cause the motor to __________.
a)
run fast
b)
hum when energized
c)
spark at the brushes
d)
fail to start
159.
A voltmeter is connected in a circuit in_____________.
a)
relay
b)
series
c)
series parallel
d)
parallel
160.
An AC generator is prevented from becoming motorized by the use of a/an __________.
a)
over speed trip
b)
reverse power relay
c)
back pressure trip
d)
governor controls
161.
An open armature connection in a DC propulsion motor could be caused by __________.
a)
low-load operation
b)
clogged ventilation ducts
c)
sparking at the brushes
d)
a grounded shunt field coil
162.
Before using rubber gloves when working on high voltage equipment the gloves should be ________.
a)
brand new
b)
cleaned inside out
c)
oiled inside and out
d)
tested t withstand the high voltage
163.
Conducting materials such as copper, aluminum and tungsten____________.
a)
increase in resistance with in increased temperature
b)
increase in resistance with decreased temperature
c)
decrease in resistance with in increased temperature
d)
increase in conductance with increased temperature
164.
Electrical leads and insulation on a motor should be painted with _________.
a)
insulating varnish
b)
heat resisting aluminum
c)
heat resisting acrylic
d)
insulating white lead
165.
How is a wattmeter electrically connected in a circuit?
a)
In series
b)
In parallel
c)
In series-parallel
d)
Inductively
166.
If field excitation is lost to an alternator operating in parallel with others, that alternators will_______________.
a)
reverse direction of rotation and over speed
b)
continue to operate at no load
c)
lose of its load and over speed
d)
become overloaded and slow down
167.
In a 60 Hz AC system, the current will pass through one complete cycle in __________.
a)
60 seconds
b)
6 seconds
c)
1 second
d)
.016 of a second
168.
In an induction motor with a cage rotor, the full load stator current is approximately_________times the running current.
a)
two
b)
three
c)
five
d)
nine
169.
It is a cylindrical core mounted on a shaft with an insulated direct current winding, arranged to produce magnetic poles on its outer periphery of an alternator.
a)
Motor
b)
Armature
c)
Rotor
d)
Stator
170.
It is an electric switch where a circuit is connected to one part of another circuit in one position of a switch and to another part of the circuit in the other position.
a)
Multi pole
b)
Double throw
c)
Double pole
d)
Single throw
171.
It is the reason why cargo pumps onboard tanker vessel are run or powered by steam.
a)
Avoid spill
b)
Easier maintenance
c)
Reduce cost
d)
Avoid ignition
172.
Motor controllers or starter contracts may become pitted and welded together if the contacts are ________.
a)
opened under loaded condition
b)
closed slowly with light pressure
c)
opened too quickly and arc
d)
closed quickly with proportionate pressure
173.
Prior to hydraulic system being activated and when it is being closed down what proper procedure must be made to ensure its safe operation?
a)
operators should ensure that pressure gauges are at the minimum level when in operating
b)
ensure that there are no pockets of air trapped pressure in the system
c)
operator should ensure that all pressures have been in the minimum before disconnecting any line
d)
any spillage of hydraulic oil should be reported to responsible officer
174.
Switchboard of an AC generators would be equipped with a____________.
a)
frequency meter
b)
governor control
c)
voltmeter
d)
all of the given answers
175.
The charge of a lead-acid battery is checked with a __________.
a)
manometer
b)
hydrometer
c)
viscosimeter
d)
ohmmeter
176.
The differential height of the left hand side of the tube from the zero mark to the open end for device "C" is 4.4". If the barometric pressure is 14.7 psia, and the "U" tube contains mercury, what minimum pressure applied to "A" would just force the li
a)
4.32 psia
b)
4.32 psig
c)
29.92 psia
d)
2.16 psig
177.
The end current that will flow in a 9 ampere current that passes in a resistor of 20 ohms and 40 ohms connected in parallel will be_____________.
a)
3
b)
6
c)
9
d)
12
178.
The instrument being used to measure the atmospheric pressure is called a ____________.
a)
Barometer
b)
Pneumercator
c)
Compound Gauge
d)
Pressure Gauge
179.
The most common material that is being used in producing electricity for powerful use is_____________.
a)
solution
b)
chemicals
c)
magnets
d)
electrodes
180.
The parts of a generator where the end of an armature coils one connected that also rotate with the armature is called _____________.
a)
Carbon brushes
b)
Slip rings
c)
South poles
d)
North poles
181.
The quantity or condition which is measured and controlled is known as the __________.
a)
controlled variable
b)
manipulated variable
c)
set point
d)
control point
182.
The small variable shunt connected across the series field coils to permit adjustment of the degree of compounding is called_____________.
a)
Diverter
b)
Divider
c)
Resistor
d)
Rheostat
183.
The total voltage and amperage of two 50-amp 6-volt batteries connected in series is;
a)
12 volts, 50 amps
b)
12 volts, 100 amps
c)
6 volts, 10 amps
d)
6 volts, 50 amps
184.
Theoretically, if the "B" end of the hydraulic transmission illustrated were provided with a variable position tilting box, and the "A" end displacement were to be constant, the __________.
a)
speed output of the "B" end would decrease in proportion as the tilting box would approach zero stroke
b)
available horsepower at the "B" end would increase in proportion as the tilting box would approach zero stroke
c)
speed output of the "B" would increase in proportion to increasing the "B" end tilting box angle
d)
available horsepower at the "B" end would increase in proportion to the increasing angle of the "B" end tilt box angle
185.
Three resistors of 100, 120, and 150 ohms are connected in parallel. Determine value of current to parallel system which will make current in 120 ohms resistors equal to 1.0 amp.
a)
I= 3 amps.
b)
I= 2 amps.
c)
I= 4 amps.
d)
I= 1 amps.
186.
Two contributors of electronic console failures are heat and vibration. To combat some of their effects, preventive maintenance procedures should include __________.
a)
systematic rotation of circuit cards with those from spares to allow component cooling
b)
periodic changing or cleaning of console ventilation and control room air conditioning filters
c)
daily inspection of console foundation bolts
d)
all of the above
187.
What condition indicate (s) that a lead-acid battery is being charged too quickly?
a)
unusually high electrolyte specific gravity
b)
low plate potentials
c)
sparking at the positive terminal
d)
excessive temperatures and excessive gassing
188.
What is the approximate discharge voltage produced by one cell of a wet type nickel-cadmium battery?
a)
1.25 volts
b)
1.5 volts
c)
2.2 volts
d)
6.0 volts
189.
What is the true concerning single parallel resistance circuits?
a)
the total current flow equals the reciprocal of the sum individual currents
b)
the total resistance equals the sum of the individual resistance
c)
the total current flow equals the sum of the individual currents
d)
the total voltage equals the sum of the individual voltages
190.
What kind of overload relay that can well protect a motor against high ambient temperature or inadequate ventilation that can also be adjusted either manual or automatic resetting?
a)
Electronic
b)
Thyristor
c)
Magnetic
d)
Thermal
191.
What will happen to the alternator frequency if the load is removed from a turbo charger whose governor a 3 percent speed drop?
a)
it will remain unchanged
b)
it will decrease approximately 3 percent
c)
it will become variable
d)
it will increase
192.
When operating an AC generator on a 3-phase 4-wire system, the neutral wire__________.
a)
maintains equal current in each phase
b)
maintain equal power in each phase
c)
maintains equal voltage in each phase
d)
has no current flow when the loads are unbalanced
193.
When troubleshooting a console circuit card suspected of being faulty, first check for proper voltages to the card and then __________.
a)
test transistors or integrated circuits for gain and compare with manufacturer's specifications
b)
blow any accumulated dust from the card with at least 30 psi air from the ship's service air system
c)
pull the card, clean the sliding connections with a pencil eraser, and remove accumulated dust
d)
de-energize the card and check the printed circuit traces for continuity with an ohmmeter
194.
Which of the following characteristics is most critical in determining the size of the cable to be used in a particular circuit?
a)
voltage rating
b)
weight per unit length
c)
current rating
d)
inductance per unit length
195.
Which of the following problems will occur if the circuit breaker of the incoming alternator is closed and it is 180° out of phase with the loaded alternator when paralleling?
a)
The rotor of the loaded alternator will hunt.
b)
Severe cross currents will occur which could cause damage.
c)
The rotor of the incoming alternator will stop.
d)
Both alternators will parallel 180° out of phase.
196.
Which of the following would you not normally find on a DC generator?
a)
Binding wires
b)
Slip rings
c)
Brush holder
d)
Air gap
197.
Which type of flux should be used when soldering electrical wire connections for electronic components on printed circuit boards?
a)
Silver flux
b)
Rosin flux
c)
Solid flux
d)
Acid flux
198.
A circuit breaker for a 300 KW alternator is rated at 470 amperes of full continuous load. The amount of overcurrent allowed is 125%. Which of the following conditions will trip the breaker?
a)
Sustained current flow of 470 amperes.
b)
Sustained current flow of 500 amperes for 10 minutes.
c)
Momentary starting load of 550 amperes.
d)
Sustained current flow of 590 amperes.
199.
A four-pole, 60 cycle, squirrel-cage motor has a full load speed of 1725 RPM. What will be the percent of slip at full load?
a)
4.16
b)
4.34
c)
95.66
d)
95.84
200.
A megger is________________.
a)
an instrument for measuring current
b)
a hand-cranked AC generator
c)
a hand-cranked DC generator
d)
use for measuring thickness
201.
A shore power circuit breaker should be closed only __________.
a)
when the ship's generators have been directly paralleled to those on shore
b)
in a shipyard
c)
if a quick disconnect coupling is used
d)
when the ship's generators have been removed from the bus
202.
A voltmeter is connected in a circuit in_____________.
a)
relay
b)
series
c)
series parallel
d)
parallel
203.
An "instantaneous-trip" type fuse will __________.
a)
open as soon as the load current exceeds its set point
b)
allow a preset delay between over current and melting
c)
open a circuit by using a time delay element with a magnetic trip
d)
reset itself when the over current is corrected
204.
An ohmmeter used to test for front-to-back resistance of a PN junction diode should produce roughly what ratio?
a)
100:1
b)
500:1
c)
1000:1
d)
5000:1
205.
Before using an all-purpose electric measuring instrument (multimeter) utilizing internal batteries to supply power for resistance measurements, you should FIRST __________.
a)
remove one of the batteries
b)
remove all the batteries
c)
calibrate using a known external resistance
d)
select the proper resistance range and calibrate the meter for "zero" ohms
206.
Conducting materials such as copper, aluminum and tungsten____________.
a)
increase in resistance with in increased temperature
b)
increase in resistance with decreased temperature
c)
decrease in resistance with in increased temperature
d)
increase in conductance with increased temperature
207.
Electrical leads and insulation on a motor should be painted with __________.
a)
insulating white lead
b)
insulating varnish
c)
heat-resisting aluminum
d)
heat-resisting enamel
208.
How does an ohmmeter behave if its positive lead is connected to cathode of a diode while negative to anode?
a)
has very low resistance
b)
has decreasing resistance
c)
has unstable resistance
d)
has infinite high resistance
209.
If field excitation is lost to an alternator operating in parallel with others, that alternators will_______________.
a)
reverse direction of rotation and over speed
b)
continue to operate at no load
c)
lose of its load and over speed
d)
become overloaded and slow down
210.
In a 15 HP induction-type motor with a cage rotor, the current required at standstill to produce starting torque is approximately __________.
a)
half the full load current
b)
equal to the full load current
c)
five times the full load current
d)
ten to twenty times the full load current
211.
In an induction motor with a cage rotor, the full load stator current is approximately_________times the running current.
a)
two
b)
three
c)
five
d)
nine
212.
It is a cylindrical core mounted on a shaft with an insulated direct current winding, arranged to produce magnetic poles on its outer periphery of an alternator.
a)
Motor
b)
Armature
c)
Rotor
d)
Stator
213.
It is an electric safety device that automatically breaks the current if an excessive current is drawn by the motor.
a)
Power relay
b)
Overload relay
c)
Load equalizer
d)
voltage regulator
214.
It is the part of the generator that carries the generated alternating current to the load.
a)
armature
b)
commutator
c)
carbon brush
d)
slip rings
215.
Motor controllers are seldom troubled with grounds because __________.
a)
the auxiliary contacts have a high resistance connection
b)
the contactors and relays are mounted on a non-conducting panel
c)
the resistor banks are composed of individual series-connected units
d)
there are separate switches for the motor and the control
216.
Prior to entry into a large DC propulsion motor housing for maintenance purposes you should __________.
a)
de-energize and lock out thermal heater circuits and any other auxiliary circuits located inside the motor housing
b)
tag and lock out the motors main circuit breaker
c)
engage shaft brake to prevent rotor from turning
d)
All of the above
217.
Switchboard of an AC generators would be equipped with a____________.
a)
frequency meter
b)
governor control
c)
voltmeter
d)
all of the given answers
218.
The charge of a lead-acid battery is checked with a __________.
a)
manometer
b)
hydrometer
c)
viscosimeter
d)
ohmmeter
219.
The difference between the synchronous speed of an three phase induction motor and its operating speed is called slip and may be correctly expressed as _________.
a)
a percent of synchronous speed
b)
the reduced amp rating
c)
the decrease in shaft torque
d)
all of the above
220.
The end current that will flow if a 9-ampere current will flow in a resistor of 20 ohms and 40 ohms connected in parallel.
a)
3
b)
6
c)
9
d)
12
221.
The instrument being used onboard to measure the pressure of the atmosphere is called ___________.
a)
Barometer
b)
Compound Gauge
c)
potentiometer
d)
Pressure Gauge
222.
The most common material that is being used in producing electricity for powerful use is_____________.
a)
solution
b)
chemicals
c)
magnets
d)
electrodes
223.
The parts of a generator where the end of an armature coils one connected that also rotate with the armature is called _____________.
a)
Carbon brushes
b)
Slip rings
c)
South poles
d)
North poles
224.
The pushbutton on the handset of a ship's sound-powered telephone must be depressed to __________.
a)
talk then released to listen
b)
listen then released to talk
c)
both talk and listen
d)
ring the station being called
225.
The small variable shunt connected across the series field coils to permit adjustment of the degree of compounding is called_____________.
a)
Diverter
b)
Divider
c)
Resistor
d)
Rheostat
226.
The total voltage and amperage of two 50-amp 6-volt batteries connected in parallel is;
a)
6 volts, 100 amps
b)
6 volts, 50 amps
c)
12 volts, 100 amps
d)
12 volts, 50 amps
227.
Theoretically, a double suction impeller is in hydraulic axial balance. In actuality this balance is rarely achieved due to __________.
a)
an unbalanced force exerted from the direction of the impeller nearest the driving motor
b)
unequal or nonuniform flow to the suction eyes of the impeller housing
c)
excessive sealing water flow to the stuffing box
d)
flexible shaft design which causes rapid wear of the outboard shaft bearing
228.
Three factors responsible for the change in voltage as load is applied to an AC generator are: 1) the drop in resistance in the armature circuit, 2) the change in flux, and 3) the __________.
a)
armature winding speed
b)
inductance load drop
c)
coil pitch factor
d)
armature reactance voltage drop
229.
Two contributors of electronic console failures are heat and vibration. To combat some of their effects, preventive maintenance procedures should include __________.
a)
systematic rotation of circuit cards with those from spares to allow component cooling
b)
periodic changing or cleaning of console ventilation and control room air conditioning filters
c)
weekly tightening of console foundation bolts and changing of the air in the control room
d)
all of the above
230.
What condition can result if dirt and grease are allowed to accumulate between the commutator segments of a motor?
a)
a dead short circuit
b)
misalignment of the motor
c)
a partial short circuit
d)
overspeeding of the motor
231.
What is the advantage of a PN diode over a vacuum diode?
a)
longer life
b)
no warm up time
c)
less delicate
d)
all the given answers
232.
What is the true concerning single parallel resistance circuits?
a)
the total current flow equals the reciprocal of the sum individual currents
b)
the total resistance equals the sum of the individual resistance
c)
the total current flow equals the sum of the individual currents
d)
the total voltage equals the sum of the individual voltages
233.
What kind of motor starter that reduce current and starting tarque in the same proportion?
a)
Auto transformer starter
b)
Magnetic line strater
c)
Solid state starter
d)
Reduced voltage starter
234.
What will happen to the alternator frequency if the load is removed from a turbo charger whose governor a 3 percent speed drop?
a)
it will remain unchanged
b)
it will decrease approximately 3 percent
c)
it will become variable
d)
it will increase
235.
When operating an AC generator on a 3-phase 4-wire system, the neutral wire__________.
a)
maintains equal current in each phase
b)
maintain equal power in each phase
c)
maintains equal voltage in each phase
d)
has no current flow when the loads are unbalanced
236.
When trouble shooting motor controllers, a shorted relay or contactor coil is often indicated by _________.
a)
a higher than normal voltage reading across the winding
b)
charged insulation and or a blown control fuse
c)
a reading of zero on a megger from one of the coil is to ground
d)
a resistance reading of infinity on a ammeter
237.
Which of the following characteristics is most critical in determining the size of the cable to be used in a particular circuit?
a)
voltage rating
b)
weight per unit length
c)
current rating
d)
inductance per unit length
238.
Which of the following problems will occur if the circuit breaker of the incoming alternator is closed and it is 180° out of phase with the loaded alternator when paralleling?
a)
The rotor of the loaded alternator will hunt.
b)
Severe cross currents will occur which could cause damage.
c)
The rotor of the incoming alternator will stop.
d)
Both alternators will parallel 180° out of phase.
239.
Which of the following would you not normally find on a DC generator?
a)
Binding wires
b)
Slip rings
c)
Brush holder
d)
Air gap
240.
Which type of flux should be used when soldering electrical wire connections for electronic components on printed circuit boards?
a)
Silver flux
b)
Rosin flux
c)
Solid flux
d)
Acid flux
241.
A circuit breaker for a 300 KW alternator is rated at 470 amperes of full continuous load. The amount of over current allowed is 125%. Which of the following conditions will trip the breaker?
a)
Sustained current flow of 470 amperes.
b)
Sustained current flow of 500 amperes for 10 minutes.
c)
Momentary starting load of 550 amperes.
d)
Sustained current flow of 590 amperes.
242.
A four-pole, 60 cycle, squirrel-cage motor has a full load speed of 1725 RPM. What will be the percent of slip at full load?
a)
4.16
b)
4.34
c)
95.66
d)
95.84
243.
A megger is________________.
a)
an instrument for measuring current
b)
a hand-cranked AC generator
c)
a hand-cranked DC generator
d)
use for measuring thickness
244.
A shore power circuit breaker should be closed only __________.
a)
when the ship's generators have been directly paralleled to those on shore
b)
in a shipyard
c)
if a quick disconnect coupling is used
d)
when the ship's generators have been removed from the bus
245.
A voltmeter is connected in a circuit in_____________.
a)
relay
b)
series
c)
series parallel
d)
parallel
246.
An "instantaneous-trip" type fuse will __________.
a)
open as soon as the load current exceeds its set point
b)
allow a preset delay between overcurrent and melting
c)
open a circuit by using a time delay element with a magnetic trip
d)
reset itself when the overcurrent is corrected
247.
An ohmmeter used to test for front-to-back resistance of a PN junction diode should produce roughly what ratio?
a)
4.167361111
b)
20.83402778
c)
41.66736111
d)
208.3340278
248.
Before using an all-purpose electric measuring instrument (multimeter) utilizing internal batteries to supply power for resistance measurements, you should FIRST __________.
a)
remove one of the batteries
b)
remove all the batteries
c)
calibrate using a known external resistance
d)
select the proper resistance range and calibrate the meter for "zero" ohms
249.
Compressed air should not be used to clean motor controller equipment because__.
a)
It may force metallic particles into coil insulation
b)
The surrounding area may heed additional cleaning
c)
The air blast dries out insulation quickly
d)
A mask and respirator would be required
250.
Electrical leads and insilation on a motor should painted with
a)
heat-resisting enamel
b)
heat-resisting aluminum
c)
insulating varnish
d)
insulating white lead
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