Electrician Training Flashcards
1
Q
The symbol for coulumb is:
A
Q
2
Q
kV =
A
1000 volts
3
Q
mV =
A
1/1000 volts
4
Q
MV =
A
1,000,000 volts
5
Q
uV =
A
1/1,000,000 volts or .000001 volts
6
Q
1 coulomb =
A
6.28 x 10 18
7
Q
1 HP =
A
746 Watts
8
Q
What is the power equation used when voltage and resistance is provided
A
P = The voltage squared divided by the resistance
9
Q
What term applies to the use of two or more Generators to supply a common load
A
Parallel operation
10
Q
DC Generators use slip rings to
A
Slip rings only for AC
11
Q
Auto transformer starters are Sometimes use with Three phase induction motors to
A
Reduce start up voltage applied to the motor during start
12
Q
What are the subatomic particles of Individual elements
A
Neutron protons electrons
13
Q
List two fundamental properties of insulation
A
Dielectric Strength , Insulation resistance
14
Q
Define the atoms Valence shell
A
The outer layer of an atom
15
Q
Power wire size listed on ships
A
AWG or Circular mil
16
Q
What makes up a magnetic field
A
Intensity and density
17
Q
Highly magnetic material can be used to Shield from magnetic flux interference and is
A
Temporary ring magnetic
18
Q
Conductors have three or less electrons in their
A
Valence Shell
19
Q
What is the one-way valve in electrical circuits
A
Diode
20
Q
Capacitors are measured in units called
A
Farads
21
Q
Material that are easily magnetized are photo electric materials true or false
A
False
22
Q
The unit of electrical resistance is the
A
Ohm
23
Q
The greatest single cause of electrical resistance is the
A
High inductance
24
Q
Which of the listed device is used to measure pressure and convert it to electrical signal
A
Transducer
25
Ohm meters are usually used to take resistance reading True or false
True
26
When taking resistance reading the circuit should be energized true or false
False
27
What meter is used to check for continuity of electrical circuits or devices?
Ohm meter (measures continuity or open line)
28
A megohmmeter is Widely used for measuring insulation resistance True or false
True
29
Electric current is the flow of electrons through a conductor the rate of this flow is measured in
Amperes
30
Electrical power is expressed in ohms true or false
False
31
Square root of two equals
1.141
32
a localized electric current induced in a conductor by a varying magnetic field.
Eddy Current
33
Oscilloscope measures
Hertz
34
What type of acid is in the lead battery
Sulfuric acid
35
What physical harm Can in arc flash blast do to you name four things
Burns Shrap Metal blinding ear damage
36
By the IEC (International electrical corporation) What is high voltage
1000 V
37
By the NEC (National electrical corporation) What is high voltage
600 v +
38
What gas is a byproduct of charging lead acid batteries
Hydrogen
39
How many electrons in a semi conductor Valence shell
4 electrons
40
How many electrons are in a Non-conductive insulation valence shell
5 to 8 electrons in the valence shell
41
Conditions that affect magnets adversely
Heat and jarring
42
Fatal shock can be caused with as little as .025 campers 0.1 amp or‘s is likely to be fatal 100ma True or false
True
43
Interrupts the excessive current by melting so that further damage to Personnel and equipment is prevented
Fuse
44
Is automatically operated electrically switch designed to protect personnel and equipment from damage caused by overloadsor short circuits. It’s functions to detect and interrupt circuit current immediately
Circuit breaker
45
Electrical fire agents
CO2, dry chemicals ,halogenated extinguishing agent’s
46
High concentration of Fluxx in core is used to move steel core in
Relays
47
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A device Designed to trip a circuit breaker when a fault is detected
Overcurrent
Overvoltage
Reverse power
Over and under frequency
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Protective relays
48
Switch gears and protection devices shall be confirmed to
IEC publication
49
Is the unit of measure used to measuring frequency as frequency Is measured In cycles per second , so one second equals?
Hertz
50
a device used In an Electrical Circuit to change alternating current to direct current
Rectifier
51
Cycles per second
Hertz
52
Capacitance is the property of an electric circuit opposing change in what value of a circuit
Voltage in the circuit
53
What is the basic unit of measure for inductance
Henry
54
As a property of an electric circuit how is inductance correctly described
Opposes any change in the current flow through the circuit
55
A direct current passes through a wire coiled around a soft iron core is known as what
Electro magnet
56
An accidental path of low resistance which bypasses the intended resistance and passes an abnormal amount of current is known as what
Short circuit
57
In which unit is EMF measured
Volts
58
And adjustable resistor whose Resistance can be changed without opening the circuit in which it is connected is called
Rheostat
59
When a main electrical cable is run from the vessels switchboard to a distant light panel it is called a
Feeder cable
60
If the motor of the circuit fails to start and gives a loud hum when the start button is pushed what is most likely the problem
And open overload OL heater
61
In the Motor controller, the motor fails to start a volt meter reading between one and five reads line voltage while the volt meter reading between two and five reads 0 VAC. What is most likely the problem
And open stops switch contact(When not pushed in)
62
The motor fails to start and gives A loud hum when the start button is depressed what should then be your first action
Push the start button to De-energize the “M” coil
63
The motor fails to start on an attempt start up. with the start button depressed, a volt meter reading between one and five Indicates line voltage available to the control circuit. what should be your next step in the troubleshooting process
Attempt to reset the Overload relay And determine the cause of the overload if applicable
64
The motor starts when the start button is pushed, but stops when the button is released. What is most likely the trouble
And open Auxiliary “M” contact
65
GFCI
Ground fault circuit inductor
66
Three matching factors to parallel a generator
Frequency, Voltage, Phase orientation or Phase are Aligned
67
What determines a generator output voltage? And frequency?
The strength of the voltage going through the coils and speed of rotation for the frequency
68
Two shock boundaries
Limited and approach boundary
69
Converting (rectifier)
AC to DC
70
Inverting
DC to AC
71
How is a generator output voltage controlled?
AVR Automatic voltage regulator
Convert AC to DC current and controls current to the windings on the main pole
72
What determines a transformers ratio
The number of turns in a coil
73
Magnet. Conductor. What needs to happen to create
Relative motion
74
What device uses magnetic induction to operate
Contactor
75
What needs to rectify a AC to DC
Rectifiers capacitors
76
A commentator is a
Slip ring on a DC
77
Temporary ring magnets are extensively used to
Shield instruments and components from the effects of magnetic flux
78
What type of material are considered to magnetize easily
FerroMagnetics
79
Major disadvantage of a series DC Generator is
Output voltage varies as the load varies
80
Lap windings used in AC generators are
Does not use an AC generators
81
Which method listed is used to start Field excitation in a DC generator
Residual magnetism Remaining in the field poles
82
Magnetic induction occurs when there is Relative motion between What two elements
Magnetic field And conductor
83
What are two basic types of alternators
Rotating Armature and rotating field
84
The use of a shunt in an ammeters For measuring current provides
Low Resistance to keep higher Currents From the meter coil
85
Ferromagnetic material can be used to Focus the
Flux in the core of the transformer
86
What are the three categories (material properties ) Of elements that refer to their interaction with electricity
Conductor, semi conductor, insulator
87
Line voltage equals the phase voltage in the
Delta configuration
88
Convert 0.5A to mA
500mA
89
If you’re going to bring up another generator to the electrical ring bus you’re going to have to
Close your breakers (generator circuit breaker) Then parallel the generator to the electrical ring bus
90
And Adam that loses or gains electrons is
Ionized
91
Is the unit of capacitance
Farads
92
Is the unit of inductance
Henry
93
A current of .2 campers or greater can cause
Death severe burns unconsciousness
94
Heat stress condition if you’re in a space 100° and above you must be out of the space
Double the amount that you were in the space ( if you’re in a space for eight hours at 100° you must be out of the space for 16 hours in order for your body to recover if the space humidity is 90% but the space temperature is 97° constitute you must be out of the space double the amount of time you’re in the space
95
What are the three things that causes electromagnetic induction
Conductor, flux and relative motion
96
What are the three classifications of DC generators
Series, shunt, compound
97
Magnetic induction occurs when there is relative motion between what two elements
Magnetic field and conductor
98
A Voltage of a generator is at 325 that has no load, And 300 at full load, what is the Generators voltage regulation
E no load minus E full load Multiply by 100 equals regulation (Refer to page 20 lesson 32)
99
If A step down transformer has a ratio of 8 to 1 and the secondary is 3 amps and the Primary voltage is 230 V AC what is the power on the load
86.25 Not sure if this is right
100
How do you change the frequency of a AC generator
Change the speed of them input motor
101
Inner poles Accomplish the same thing as
Compensating windings Refer to page 7 lesson 33
102
A inductive reactance load is expressed in
Ohms Reactance is resistance
103
Auto transformers help start motors by
Reducing the voltage applied to the motor during the start up period
104
What causes a voltage to develop across a secondary winding of a transformer
A magnetic line generated by the current in the primary cuts the secondary winding because it creates Fluxx and inducing a voltage
105
When copper is heated electric current is
Reduced when copper is heated resistance goes up
106
A battery rated at 400 amp hours with a specified discharge rate of 20 Amps Will last for how many hours at 5 amp discharge rate
80 hours (400/5 =80)
107
Why is it necessary to take airgap readings on motor generator equipment
Bearings can wear and introduce uneven fluxx coupling
108
What are the two main types of cores used in transformers
Shell type and hollow type
109
What’s best used on ships stranded wire or solid wire
Stranded wire
110
INTERPOLes compasate
Windings
111
What is the minimum charge of a battery
1.25
112
Tool to check battery fluid
Hydrometer
113
Two temperature sensing device aboard ships
Resistance thermal Device (RTD) thermal sensing device
114
What is the primary determining factor in selecting a conductor size
The current carrying capacity is based on its physical size
