Dc/Ac Final
The largest AWG size is which has an area of 211,600 circular mills.
0000
An ohmmeter should always be readjusted to when the scale is changed.
0zero
Rule for base of a ladder
1 foot for every 4 feet
Although inductors have some amount of resistance, inductors that have a Q of or greater are generally considered to be pure inductors.
10
A series circuit contains four resistors and the total resistors have values of 70 ohms, 80 ohms, and The resistance of the circuit is 420 ohms. The value of the fourth resistor is
100 ohms.
A rheostat is a variable resistor with terminals.
2
Article of the National Electrical Code deals with conductors used for general wiring.
210
If four resistors, each with a value of 100 ohms, are connected in parallel, the total resistance of the circuit is
25
Resistors that have a tolerance of plus/minus 20% have color bands.
3
A potentiometer is a variable resistor with terminals.
3.
resistor with bands of yellow, violet, red, and silver would have a value and tolerance of what?
4,700
A series circuit has individual resistance of the circuit is resistor values of 200 ohms. 150 ohms, 50 ohms, and 75 ohms. The total
475 ohms.
The exponential curve describes a rate of certain occurrences and is divided into time constraints.
5
time constants are required to charge or discharge a capacitor.
5
Three resistors, with values of 10 ohms, 20 ohms, and 30 ohms, are connected in parallel and the circuit has a voltage of 120 volts with The total current 20-ohm branch is
6
The most common frequency used in electrical generation in the United States and Canada is hertz,
60
Each time constant of an exponential curve is equal
63.2 Percent
If a parallel circuit has two resistors with values of 10 ohms and 25 ohms, the total resistance of the circuit is ohms.
7.14
A U.S. military study showed that a capacitor operated at one-half its rated voltage will have a life span about times longer than a capacitor operated at its rated voltage.
8
is a line that indicates both magnitude and direction.
A Vector
The total amount of resistance to current flow in a series circuit is equal to the sum of the in that circuit.
A and B
A device that can be used for voltage spike suppression in either AC or DC circuits is the
AMelal oxide varistor.
If more than three conductors are to be used in a raceway, the ampacity of the conductors must be
Adjusted
The temperature of the surrounding air is called the
Amblent air temperature.
angular displacement by which voltage and current are out of phase with each other
Angle theta
What occurs when an intermittent gap between conductors or a conductor and ground permits current to jump between two conductive surfaces.
Arc-Fault
A class _____ fire involves grease, combustible liquids, or gases.
B
A class ____ fire involves energized electrical equipment.
C
are used in industrial applications for power factor correction, as well as in the start windings of many single-phase motors.
Capacitors
Although not considered in the circuit calculations of most circuits, inductance is considered in the circuit calculations of couls that contain motors tranfomers lighting that all contain ____ of wire
Coils
The value of a resistor can often be determined by use of the
Color code
Before current can flow through a circuit, a _____ must exist
Complete path
A ____ is generally made for materials that contain one or two valance electrons
Conductor
A good rule to remember concerning capacitors is that can only flow during time that a capacitor is either charging or discharging.
Current
The advantage of high-voltage transmission is that lessCurrent is required to produce the same amount of power.
Current
In parallel circuits, when all resistors are of equal value the total resistance is equal to the value of one individual resistor
Divided by the number Of resistors
a(n) The ground point that is made by physically driving an object, such as a ground rod, into the ground is called
Earth ground.
When determining the conductor size for a particular application, you are determining the maximum current a conductor can carry.
False
A capacitor has capacitance of one when a change of one volt across its plates results in a movement of one coulomb.
Faret
resistors have only one ohmic value, which cannot be changed or altered.
Fixed
When using the color code to determine the value of a resistor, the band is the tolerance band, when the tolerance of the resistor is 5% or 10%.
Fourth
A -wave rectifier is one that changes both positive half and the negative half of the AC wave form into DC.
Full
A conductor connected to the case of an appliance to provide a low-resistance path to ground is called a _____ conductor
Grounding
Electrical current will flow through the ______ conductor only when a circuit fault develops
Grounding
The polarity of the voltage is determined by the polarity of the magnetic field in relation to the direc of movement.
Induced
When reading an ohmmeter scale, the value of resistance shown at the far left end of the scale is
Infinty 8
Never work on an energized circuit unless
It is not possible to disconnect the power
Reactance is symbolized by the letter
L
In a pure capacitive circuit, the current
Leads the applied volatge by 90 degrees
The most common way for producing electricity is
Magnetism
When using the color code to determine resistor values, the third band is called the band.
Multiplier
The amount of current leaving the source
Must equal the current returning to the source
A _____ charge formed by an excess of electrons
Negative
The mission of the ____ is to ensure safe and healthful workplaces in the United States.
None
capacitors are not sensitive to polarity connection.
Nonpolarized
A ______ is the amount of resistance that allows one ampere of current to flow when the applied voltage is one volt
Ohm
I'm it's simplest form, ____ states that it takes one volt to push one amp through one ohm
Ohms law
Polarized capacitors can be in
Only DC
is the ratio of true power to apparent power.
Power Factor
The Q
Quality.
When a capacitor is connected in a circuit with a resistor, the amount of time needed to charge the capacitor time constant.
RC
The AC voltage that will produce the same amount of power as a like value of DC voltage is called the value,
RMS
A is used to change alternating current into direct current.
Rectifier
In a parallel circuit,the amount of current flowing through each resistor is inversely proportional to its
Resistance
RMS stands
Root mean square
21. A circuit is a circuit that has only one path for the current to flow.
Series
The most common of all AC waves is the
Sine wave.
A large amount of voltage that exists for a very short period of time is called a voltage
Spike
Alternating current can be for the purpose of transmission and then when it is 'to be used by a device.
Steped up/Down
The stretching of the atoms of the dielectric is called dielectric
Stress
NEC® 110.14(C) states that the temperature rating of a conductor must be selected so as not to exceed lowest temperature rating of any connected conductor, termination or device.
True
When determining conductor size for an area where ambient temperature is a concern, you must divide the needed current by the correction factor.
True
Reactive power is measured in
VARS
Any electron located in the outer shell of an atom are known as _____ electrons
Valence
capacitors generally contain a set of moveable plates that allow capacitance to be changed.
Variable Capacitors
______ is defined as electromotive force
Volt
is the force that pushes the electrons through a resistance.
Voltage
are the number of turns of wire, the strength of the magnetic field, the speed of the cutting action.
Voltage Induced
are used to provide different voltages between certain points of a circuit.
Voltage dividers
indicates the amount of voltage necessary to push the current through the limiting element.
Voltage drop
The test instrument used to measure voltage in a circuit is called
Voltmeter
Electrical energy must be changed or converted into some other form of energy before there can be
Watts
all the parts of the circuit,
Watts
resistors can operate at higher temperatures than any other type of resistor.
Wire wound
Impedance is symbolized by the letter
Z
The amount of voltage required to push the electrons through the circuit is determined by the amount of
a and b
Which of the following conditions must be met before conductors are permitted the NEC to be run in parallel?
a and c only
A circuit with little or no resistance in it is called
a short circuit
If a clamp-on ammeter is clamped around more than one power line of a 240 V circuit, the meter will read volts.
a.
resistors are fixed resistors that are made by winding a piece of resistive wire around a ceramic core.
a.None of the above
Carbon resistors will change their value because of
age overheating either a or c
In a parallel circuit, the total resistance is equal to the
all of the above only
The unlike the voltmeter, is a very low-impedance device.
ammeter
In a series circuit, the is the same at any point in the circuit.
amperage
If a series circuit has three resistors and two amps flow through each resistor, the total amperage for the circuit is
amps. 2
A wire's ability to carry current is known as its
anmpacity.
The total amount of power in a circuit is equal to the sum of the power used by all the parts.
any of the above
The power of a resistive-inductive series circuit can be found when a voltmeter and ammeter are used to measure the circuit voltage and current and then these measured values are multiplied together.
apparent
Digital meters that do not contain a range setting control are known as meters.
autoranging
The value must be found when a sine wave AC voltage is changed into direct
average
Probably the greatest single advantage of alternating current is that it can
be trans formed.
When the voltage to the capacitor becomes too great, the dielectric breaks down and allows current to flow between the plates, resulting in the capacitor
becoming shorted
Nonpolarized capacitors can be used in
both AC and DC
When a capacitor is connected to a DC circuit and the voltages across both plates are equal, the flow electrons stops and the capacitor is
charged
According to Ohm's law, an increase of resistance must cause a proportional decrease of
current
Each completed wave form of a sine wave is called a(n)
cycle cycle
A location that is covered and not likely to be saturated by water is a
damp
A circular mil is the of the wire in mils squared.
diameter
The insulating material used in capacitors is called the
dielectic
The voltage rating of a capacitor is actually the voltage rating of the
dielertric
A location that snot normally subject to dampness or wetness is called a location.
dry
Reversing the polarity of a -type electrolytic capacitor will permanently damage the capacitor.
dry
Polarized capacitors are generally referred to as
electoylitic capacitors.
The advantage of is that they can have very high capacitance in a small case.
electrolytic
A capacitor stores energy in a(n) field.
electrostatic
The basic unit of capacitance is the
farad
An inductor stores energy in a(n)
field. electromagnetic
VARS is an abbreviation
forVots Arnos Reactance
In a sine wave, the number of complete cycles that occur in one second is called a
frequency
The higher the the faster a capacitor will charge and discharge.
frequency
The standard measure of inductance is the
henry
Connecting capacitors in parallel has the effect of the plate area of one capacitor.
increasing
When reading a digital meter, the symbol "mV"
indicates_mili volts
A coil wound on a nonmagnetic core material such as wood or plastic is referred to as
inductor. air core
The reciprocal of any number is that number divided
into 1
A coil wound on a core made of magnetic material such as silicon steel or soft iron is referred to as a(n)
iron core
The current in a pure resistive circuit
is in phase with the applied voltage
The disadvantage of the metal film resistor is that
it costs more than carbon resistors
The current in a pure inductive circuit
lags the applied voltage by 90 degrees
In the early days of electric power generation, Thomas Edison proposed powering the country with
low-voltage direct current
The principle of states that whenever a conductor cuts through magnetic lines of flux, a voltage is induced into the conductor.
magnetic induction
A device that measures insulation resistance in millions of ohms is called a(n)
megger
A is a piece of wire one foot long and one mil in diameter.
mil-foot
When working with electrical equipment that requires sensitive adjustments, resistors are usually used.
multiturn variable
A point when current reaches a junction point
node
A circuit contains elements of both series and parallel circuits.
none of the above
The is used measure resistance.
ohmmeter
The must provide its own source of power.
ohmmeter
Capacitive reactance is measured in
ohms
Impedance is measured
ohms
Inductive reactance can be computed when the values of inductance and frequency are known and is
ohms
Given the voltage and the resistance, the amount of current flow in a circuit can be determined by using
ohms law
A diode permits current to flow in
one direction(s).
Square waves are generally produced by electronic devices called
oscillators
Avoltmeter is designed to be connected in with the circuit to be measured.
parallel
In a circuit, the voltage across any circuit branch is the same as the total voltage.
parallel
The total resistance of a circuit is always less than the resistance of the lowest value resistor in the circuit.
parallel
circuit has more than one path for current flow.
parallel
are circuits that have more than one path for current flow.
parallel circuits
The is measured from zero to the highest value obtained in either the positive or negative direction.
peak
d. The value is measured from the maximum value in the positive direction to the maximum value in the negative direction.
peak-to-peak
When a capacitor becomes charged, the plate with the lack of electrons has
positive.
Capacitors charge and discharge at a(n)
rate. exponential
VARS is the amount of power in a resistive-inductive circuit.
reactive
Connecting capacitors in series has the effect of increasing the distance between the plates, which capacitance of the circuit.
reduces
The pulses of pulsating direct current are often referred to as
ripple
An ammeter is used to measure current and must be connected in with the load.
series
In a circuit, the sum of the voltage drops of the individual resistors must equal the applied voltage.
series
circuit has only one path for current flow.
series
d. In a circuit, the current is the same at any point in the circuit.
series
The wave is produced by all rotating machines.
sine
When using a megger to test a circuit for grounds or shorts, the meter should be set
slightly higher than the circuit voltage
In a series circuit, the sum of the voltage drops equals
the applied voltage
indicates the plus and minus limits of a resistor's ohmic value.
tolevance Band
The across any branch of a parallel circuit is the same as the applied voltage.
voltage drop
In magnetic measurement, 100,000,000 lines of magnetic flux are equal to one
weber
The two types of electrolytic capacitors are the
wet and dry