DC
Good insulation materials such as glass and mica, have relative resistance at least _____ time that of copper
1,000,000
most digital multimeters have an input opposition to current flow of _____ M(Ohm's) for all voltage ranges except the 200 MV range, which has an opposition to current flow of 40 M(Ohms)
10
The third shell of an atom can hold ___ electrons
18
Resistors with no tolerance band have a tolerance of _____
20
Potentiometers have _____ terminals
3
The ______ is called permeability
Ability of a magnet to carry magnetic lines of force
A _____ is an electromechanical device that indicates readings by the mechanical motion a pointer
Analog Multimeter
A _____ resistor is made by applying a film of carbon to a ceramic rod
Carbon Film
_____ is a mixture of fine particles of glass or ceramic and powdered metals such as silver, platinum, or gold
Cermet
_____ force is the force needed to remove a materials residual magnetism
Coercive
____ electrification occurs when a conductor connects two objects with different charges
Conduction
A switch uses ___ electrification
Contact
A _____ is an instrument that indicates an open or closed circuit in a circuit in which all power is OFF
Continuity Checker
In an _____ circuit, there is very little resistance and a dangerously large amount of current flows
Short
In the SI system, conductance is measured in _____
Siemens
1000,000,000 lines of force per meter squared is called _____
Tesla
Name does not determine the amount of induced voltage in a coil
The direction of current flow
The greater the distance away from a magnet _____ the magnetic field
The weaker
The _____ of a resistor indicates the plus and minus limits of a resistor's ohmic value
Tolerance
What does the fourth band of color on a 4 band resistor indicate
Tolerance
A _____ coils are used for current tranformers
Toroids
____ contacts are used in high current applications because of thier melting temperature
Tungsten
A resistor whos vales can be varied over a range of values is called a _____ resistor
Variable
A _____ is the unit of 100 million magnetic lines of force cut in one second
Volt
It takes one ______ to push one ampere of current through one omh of resistance
Volt
In general, ______ use a higher voltage source and more powerful battery source than that used by ordinary multimeters
Voltmeters
Increasing the speed at which a conductor cuts the magnetic field increases the _____
Volts
A ____ is equal to one joule per second in the metric system
Watt
_____ is the ability of a device or circuit to generate reactance to oppose a changing current
Electromagnetic induction
_____ is the field produced by the current through a conductor
Electromagnetism
Voltage is also known as _____
Electromotive force
_____ current flow will be used in this class
Electron
It is believed that magnetism can be explained by _____ spin patterns that spin in the _____ direction
Electron, Same
A ______ is a substance that cannot be chemically broken down and contains atoms of only one variety
Element
The _____ is the time curve for current in a inductive resistive circuit
Exponential curve
Iron, soft steel, nickel, cobalt manganese are classified as in rare earth materials
Ferromagnetic
_____ is a material that can be easily magnetized
Ferromagnetic
_____ fuses are cartridge fuses with round ends
Ferrule
Resistors that only have one ohmic value are called _____ resistors
Fixed
One magnetic line of force per square inch is called _____
Flux density
The coefficient of a coupling is the percentage of a magnetic lines of _____ created by one coil that cut the windings of the second coil
Force
One line of force per centimeter sqaured is called _____
Gauss
A _____ consists of a block of metal that transfers the head from the resistor to the chassis
Heat Sink
The unit of measurement for inductance is the _____
Henry
A coil has an inductance of 1 _____ when a current change of one _____ per second results in an induced voltage of one volt
Henry, Ampere
Which one is not a disadvantage of rare earth magents?
High retentivity
What is the main advantage of rare earth magnets
High tesla rating
A semiconductor is a material that exhibits an electrical conductivity between that if a conductor _____ and that of an insulator _____
High, Low
Wire wound resistors are often used because they are able to operate at _____ power levels than other resistors
Higher
The strength of a coils magnetic field is affected by all of the following factors except _____
Hysteresis loss
With an electromagnet, when the number of coil turns in increased, there level of induced voltage is _____
Increased
Rowlands law involves all of the following variable except
Inductance
_____ is the opposition a circuit has to change in current due to energy stored in a magnetic field
Inductance
Abrupt removal of a power from a circuit often causes coils to fail because of _____ kick
Inductive
A _____ is a passive device that stores energy in the form of a magnetic field
Inductor
A _____ opposes a change of current
Inductor
The high voltage that is produce when the magnetic field collapse in an inductive coil is called _____?
Kick back spikes
The _____ rule for conductors can be used to determine the direction of magnetic lines of force around the conductor
Left-hand
_____ law states that voltage and current induced in an inductor oppose the force that produces it
Lenz's
A solenoid is a = electric output device that converts electrical energy into _____ mechanical force
Linear
What were early natural magnets known as
Lodestones and Leading Stones
A _____ should never be used om=n energized circuits
Ohmmeters
The greek symbol Omega represents _____
Ohms
_____ is a material that can not be easily magnetized
Parramagnetic
In a ______, energy is required to create a magnetic field, but no energyy is required to maintain a magnetic field
Permanent magnet
_____ is the measurement of the property of a core material that allows the passage of magnmetic lines of force
Permeance
A _____ temperature coefficient is an increase in the resistance of a material with an increase in temperature
Positive
A _____ are normally used as voltage dividers
Potentiometer
A variable resistor is also called a _____
Potentiometer
A variable resistor with three terminals is called a ______
Potentiometer
Resistors are normally described by electrical resistance, tolerance, _____, method of construction, and circuit application
Power Rating
The physical size of a resistor can give you the _____ of a resistor
Power Rating
The efficiency of a system is the ratio of the _____ output to the ______ input
Power, Power
_____ motion is the speed at which a conductor cuts a magnetic field
Relative
The resistance to magnetism is called _____?
Reluctance
The south pole of one magnet is broguht close to the south pole if another magnet, will the magnets repel or attract each other
Repel
_____ is the opposition to the flow of electrons
Resistance
_____ is the resistance of a material of a specific cubic size
Resistivity
Permaennt magnets have a high _____?
Retentivity
_____ is a material ability to retain magnetism
Retentivity
If the range of voltages is required, a _____ can be used in place of a resistor to provide as adjustable output voltage
Rheostat
_____ induction is the property of a conductor to induce voltage within itself due to changes
Self
Germanium and Silicon are used to make _____
Semiconductors
The conductor with the lowest resistivity is _____
Silver
Ampacity is the maximum amount of current a conductor can carry continuously without exceeding its _____ rating
Temperature
The four factors affecting the resistance of a substance are type of material, conductor length, conductor cross section area and __________
Temperature
The force of electrostatic attraction or repulsion is directly proportional to the product of the two charges and inversely proportional to the sqaure of the distance between them. This is _____ law
Coulombs Law
Heat is produced and electrical energy is consumed when _____ meets resistance
Current
The induce voltage (CEMF) is proportional to the rate of change of _____
Current
What electronic component is often used in a AC circuit to prevent large voltage spiked from being produced when the current flow through an inductor is suddenly terminated
MOV
A _____ circuit is the path taken by the magnetic lines of force
Magnetic
_____ is the current through a coil multiplied by the number of turns on the coil
Magnetomotive force
One magnetic line of force is called flux or _____
Maxwell
Megohmmeters are often referred to as Meggers _____, high voltage and insulation resistance testers
Meggers
A ______ resistor is made by applying a film of metal to a ceramic rod in a vacuum
Metal Film
A _____ resistor is made by combining metal with glass and then applying it to a ceramic base as a thick film
Metal Glaze
When applicable, the fourth band in a five band resistor represents ____
Multiplier
_____ inductance is the effect of one coil inducing a voltage into another coil
Mutual
A _____ coil is an inductor that has coils wound in such a manner that the inductance created by one coil is canceled be an adjacent coil turn
Noninductive
the power formula and _____ law can be combined to find any unknown value if two of the values are known
Ohm's
magnetic lines of force traveling in the same direction _____ each other
add to
____ meters are test instruments used to measure direct current and must have a very low resistance that does not substantially change the value of the current in the circuit
ampere
Magnetic lines of force traveling in the opposite directions _____ each other
cancel
A(n) _____ is an example of an overcurrent protection device
circuit breaker
A(n) _____ is an overcurrent protection device with a fusible link that melts and opens a circuit when an overload condition or short occurs
circuit breaker
A simple electrical circuit must have a(n) _____, a voltage source, and a load
conductor
A(n) _____ is a control device that uses a small input current to energize or de-energize the load connected to it.
contactor, control-relay, and motor starter
all switches use _____ to start or stop the flow of electrons in a circuit
contacts
In Ohm's law, the voltage of a circuit divided by the resistance is equal to the _____
current
clamp-on ammeters measure the _____ in a circuit
current
the power formula, Watt's law, is the relationship between power, voltage, and _____ in an electrical circuit
current
Lenz's law is the basic principle used to determine the _____ of an induced voltage or current
direction
to show that conductors are connected, a _____ may be places at their intersection
dot
_____ current is unwanted current caused by the rate of change in the induced magnetic field
eddy
A _____ switch is a double-pole, double throw (DPDT) switch that changes the electrical connections inside the switch from straight to diagonal
four-way
The _____ rating is the maximum amount of current that a fuse can safely interrupt without rupturing or arcing over
interrupting
A(n) _____ is a device that converts electrical energy to motion, light, heart, or sound
load
meter _____ is inaccurate readings due to the meters resistance being in parallel with the component under test
loading
an electric _____ is a rotating device that converts electrical power into a rotating mechanical force
motor
electrical measurements are most commonly taken using a(n) _____
multimeter
A(n) _____ occurs when circuit current rises above the level at which the load and or circuit is designed to operate, according to the wording per NEC
overload
_____ devices are required in motor circuits by the NEC
overload
A(n) _____ is an overload device used with motor starter that responds to electrical loads and operates at a preset value
overload relay
an Edison base _____ fuse has a screw-in base similar to a light bulb
plug
A _____ is the number of completely isolated circuits that a relay can switch
pole
A _____ is the part of a switch that determines the number of circuits the switch can control
pole
_____ is the rate of doing work or using energy
power
the _____ in a circuit increases based on a factor equal to the circuit voltage squared divided by the resistance or by the circuit current squared times the resistance
power
_____ is the amount of magnetizing force remaining after the magnetizing force is removed
residual magnetism
In Ohm's law, the voltage of a circuit divided by the current is equal to the _____
resistance
Ohm's law is the relationship between voltage, current, and _____ in an electrical circuit
resistance
A variable resistor with two terminals is called a _____
rheostat
A _____ switch is a switch that has one or more poles that can be connected to several positions
rotary
When possible, conductors being tested with a clamp on ammeter should be _____ surrounding conductors
separated from
in order to measure current flow through a component, a meter must be connected in ____ with the component
series
A _____ switch is a single-pole, double-throw (SPDT) switch
three-way
In Ohm's law, the current of a circuit multiplied by the voltage is equal to the _____
voltage
power cannot be consumed in a circuit unless there is _____
voltage
Multimeters that are set to measure _____ present high opposition to current flow
voltages
In Ohm's law, the current of a circuit multiplied by the voltage is equal to the _____
watts
The resistivity of copper is _____ cmil/ft
10.4
The valence shell or outer shell of an atom can hold a maximum of ___ electrons
8
Whish one of these magnet characteristics is not desirable in an electromagnet
Ability to retain magnetism
Some of the best permanent magnets are made from _____
All of the above
Temperature coefficient is represented in the mathematical equations by the Greek letter ______
Alpha
One _____ is one coulomb of electrons passing a given point in one second
Ampere
A ______ DMM is a DMM that automatically adjusts to a higher range if its initial range is not high enough
Autoranging
The voltage that is produced, when the electrons flow through a coil that is opposite, and opposes the source voltage is called _____?
CEMF
Relative resistance is the comparison of the resistance of a given material to the resistance of ____
Copper
Resistance of a conductor with a negative temperature coefficient _____ with an increase in temperature
Decreases
_____ is a material that can not be magnetized
Diamagnetic
The law of ____ states that opposite charges attract and like charges repel
Electric charges
It takes 5 _____ for current to reach its maximum value in a LR circuit
Time constants
One volt and one amp will produce one _____
Watt
the power formula is often referred to as ____ law
Watt's
100,000,000 lines of force is called _____
Weber
A _____ resistor is made by winding a piece of resistive wire wound around a ceramic core
Wire Wound
A _____ is a place on a switch contact that opens or closes a circuit
break
A(n) _____ circuit has no electron flow
open
Electromagnets are coils that have a core made of electrical steel or _____ material
soft steel
any switch with a ____ that holds its contacts in either the closed or open position has a normal position
spring
A _____ is a mechanical, electronic, or solid-state electrical device that is used to start, stop, or redirect the flow of electrons in an electrical circuit
switch
_____ relays operate by opening a bimetallic strip upon a rise in temperature
thermal overload
_____ and 4-way switches do not ahve ON and OFF marking on them
three-way
A _____ is the number of closed contact positions per pole of a switch
throw