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Macro Integrated Training and Review Center ElcrniX

PART17GLOSSARY

ACTIVE FILTERA frequency-selective circuit consisting of active devices such as transistors or

op-amps combined with reactive (RC) circuits.

ADMITTANCE (Y)A measure of the ability of a reactive circuit to permit current; the reciprocal of

impedance with a unit, siemens (S)

ALPHA ()The ratio of collector current to emitter current in a bipolar junction transistor.

ALTERNATING CURRENTCurrent that reverses direction in response to a change in source voltage

polarity.

AMERICAN WIRE GAGE (AWG)A standardization based on wire diameter.

AMMETERAn electrical instrument used to measure current.

AMPEREThe unit of electrical current.

AMPERE-HOUR RATINGA number given in ampere-hours determined by multiplying the current in amps

(A) times the length of time in hours (h) a battery can deliver that current to aload.

AMPERE-TURNThe unit of magnetomotive force (mmf).

AMPLIFICATIONThe process of producing a larger voltage, current or power using a smaller

input signal as a pattern.

AMPLIFIERAn electronic circuit having the capability of amplification and designed

specifically for that purpose.AMPLITUDE

The maximum value of a voltage or current.


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17-2 Glossary

ElcrniX Macro Integrated Training and Review Center

ANODEThe most positive terminal of a diode or other electronic device.

APPARENT POWER (Pa)The product of the voltage times the current, expressed in volt-amperes (VA).

In a purely resistive circuit, it is the same as the true power.

APPARENT POWER RATINGThe method of rating transformers in which the power capability is expressed in

volt-amperes (VA).

ATOMThe smallest particle of an element possessing the unique characteristics of

that element.

ATOMIC NUMBERThe number of protons in the nucleus of an atom.

ATOMIC WEIGHTThe number of protons and neutrons in the nucleus of an atom.

ATTENUATIONA gain less than unity.

AUTOTRANSFORMERA transformer in which the primary and secondary windings are in a single

winding.

AVERAGE VALUEThe average of a sine wave over one half-cycle. It is 0.637 times the peak

value.

BAND-PASS FILTERA filter that passes a range of frequencies lying between two cutoff frequencies

and rejects frequencies above and below the range.

BAND-STOP FILTERA filter that rejects a range of frequencies lying between two cutoff frequencies

and passes frequencies above and below the range.

BANDWIDTH (BW)The characteristic of a certain electronic circuits that specifies the usable range

of frequencies for which signals pass from input to output without significantreduction in amplitude.

BARRIER POTENTIALThe inherent voltage across the depletion region of a pn junction.


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Glossary 17- 3


BASEOne of the semiconducting regions in a bipolar junction transistor.

BASELINEThe normal level of a pulse waveform; the voltage level in the absence of a

pulse.

BATTERYAn energy source that uses a chemical reaction to convert chemical energy into

electrical energy.

BETA ()The ratio of collector current to base current in a bipolar junction transistor.

BIAS

The application of a dc voltage to a diode or other electronic device to producea desired mode of operation.

BLEEDER CURRENTThe current left after the total load current is subtracted from the total current

into the circuit.

BRANCHOne current path in a parallel circuit.

CAPACITANCEThe ability of a capacitor to store electrical charge.

CAPACITIVE REACTANCE

The opposition of a capacitor to sinusoidal current. The unit is the ohm ().

CAPACITIVE SUSCEPTANCE (BC)The ability of a capacitor to permit current; the reciprocal of capacitive

reactance. The unit is the siemens(S).

CAPACITORAn electrical device consisting of two conductive plates separated by an

insulating material and possessing the property of capacitance.

CATHODEThe more negative terminal of a diode or other electronic devices.

CATHODE-RAY TUBE (CRT)A vacuum tube device containing an electron gun that emits a narrow focused

beam of electrons onto a phosphor-coated screen.

CENTER TAP (CT)

A connection at the midpoint of the secondary winding of a transformer.


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17-4 Glossary


CHARGEAn electrical property of matter that exists because of an excess or a deficiency

of electrons. Charge can be either positive or negative.

CHOKEThe term is used more commonly concerning inductors used to block or choke

off high frequencies.

CIRCUITAn interconnection of electrical components designed to produce a desired

result. A basic circuit consists of a source, a load, and an interconnectingcurrent path.

CIRCUIT BREAKERA resettable protective device used for interrupting excessive current in an

electric circuit.

CIRCUIT GROUNDA method of grounding whereby the metal chassis that houses the assembly or

a large conductive area on a printed circuit board is used as the common orreference point; also called chassis ground.

CIRCULAR MILL (CM)The unit of the cross-sectional area of a wire.

CLAMPERA circuit that adds a dc level to an ac signal; a dc restorer.

CLASS AA category of amplifier circuit that conducts for the entire input cycle and

produces an output signal that is a replica of the input signal in terms of itswave shape.

CLASS BA category of amplifier circuit that conducts for half of the input cycle.

CLASS CA category of amplifier that conducts for a very small portion of the input cycle.

CLOSED CIRCUITA circuit with a complete current path.

CLOSED LOOPAn op-amp configuration in which the output is connected back to the input.

CLOSED LOOP GAIN (Acl)The overall voltage gain of an op-amp with feedback.


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Glossary 17- 5


COEFFICIENT OF COUPLING (k)a constant associated with transformers that is the ratio of secondary magneticflux to primary magnetic flux. The ideal value of 1 indicates that all the flux inthe primary winding is coupled into the secondary winding.

COILA common term for an inductor.

COLLECTOROne of the semiconducting regions in a BJT.

COMMON BASE (CB)A BJT amplifier configuration in which the base is the common (grounded)

terminal.

COMMON-COLLECTOR (CC)A BJT amplifier configuration in which the collector is the common (grounded)

terminal.

COMMON-EMITTER (CE)A BJT amplifier configuration in which the emitter is the common (grounded)

terminal.

COMMON-MODE SIGNALSSignals that appear the same on both inputs of an op-amp.

COMPARATORA circuit which compares two input voltages and produces an output in either of

two states indicating the greater or less than relationship of the inputs.

CONDUCTANCE (G)The ability of a circuit to allow current; the reciprocal of resistance. The unit is

the siemens (S).

CONDUCTORA material in which electrical current is established with relative case. An

example is copper.

COULOMB (C)The unit of electrical charge.

COULOMBS LAW

A physical law that states a force exists between two charged bodies that is

directly proportional to the product of the two charges and inverselyproportional to the square of the distance between them.


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17-6 Glossary


COVALENTRelated to the bonding of two or more atoms by the interaction of their valence

electrons.

CRYSTALThe pattern or arrangement of atoms forming a solid material.

CURRENTThe rate of flow of charge (electrons).

CURRENT GAINThe ratio of output current to input current.

CUTOFFThe nonconducting state of a transistor.

CUTOFF FREQUENCY (c)The frequency at which the output voltage of a filter is 70.7% of the maximum

output voltage.

CYCLEOne repetition of a periodic waveform.

DARLINGTON PAIRA two-transistor arrangement that produces a multiplication of current gain.

DC COMPONENT

The average value of a pulse waveform.

DECADE

A tenfold change in the value of a quantity. When a quantity becomes tentimes less or ten times greater, it has changed a decade.

DECIBEL (dB)The unit of logarithmic expression of a ratio, such as power ratio or a voltage

ratio.

DEGREE

The unit of angular measure corresponding to 1/360 of a complete revolution.

DERIVATIVE

The instantaneous rate of change of a function determined mathematically.

DIAD A semiconductive device that can conduct current in other of two directions

when properly activated.

DIELECTRICThe insulating material between the plates of a capacitor.


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Glossary 17- 7


DIELECTRIC CONSTANTA measure of the ability of a dielectric material to establish an electric field.

DIELECTRIC STRENGTH A measure of the ability of a dielectric material to withstand voltage without

breaking down.

DIFFERENTIAL AMPLIFIERAn amplifier that produces an output proportional to the difference of two inputs.

DIFFERENTIATORA circuit that produces an output that approaches the mathematical derivative

of the input, which is the rate of change.

DIODEAn electronic device that permits current in only one direction.

DISCRETE DEVICEAn individual electrical or electronic component that must be used in

combination with other components to form a complete functional circuit.

DOPINGThe process of imparting impurities to an intrinsic semiconductive material in

order to control its conduction characteristics.

DRAIN

One of the three terminals of a field-effect transistor.

DUTY CYCLEA characteristic of a pulse waveform that indicates the percentage of time that a

pulse is present during a cycle, the ratio of pulse width to period.

EFFECTIVE VALUE

A measure of the heating effect of a sine wave; also known as the rms (rootmean square) value.

EFFICIENCYThe ratio of the output power to the input power, expressed as a ratio.

ELECTRICAL

Related to the use of electrical voltage and current to achieve desired results.

ELECTRICAL ISOLATION

The condition that exists which two coils are magnetically linked but have noelectrical connection between them.


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17-8 Glossary


ELECTROMAGNETIC FIELDA formation of a group of magnetic lines of force surrounding a conductor

created by electrical current in the conductor.

ELECTROMAGNETIC INDUCTIONThe phenomenon or process by which a voltage is produced in a conductor

when there is relative motion between the conductor and a magnetic orelectromagnetic field.

ELECTRONThe basic particle of electrical charge in matter.It possesses negative charge.

ELECTRONICRelated to the movement and control of free electrons in semiconductors or

vacuum devices.

EMITTEROne of the three semiconducting regions in a BJT.

EMITTER-FOLLOWERA popular term for a common-collector amplifier.

ENERGYThe fundamental ability to do work. The unit is the joule (J).

FALLING EDGEThe negative-going transition of a pulse.

FALL TIMEThe time interval required for a pulse to change from 90% to 10 % of its full

amplitude.

FARAD (F)The unit of capacitance.

FARADAYS LAW

A law stating that the voltage induced across a coil of wire equals the numberof turns in the coil times the rate of change of the magnetic flux.

FEEDBACKThe process of returning a portion of a circuits output signal to the input in such

a way as to create certain specified operating conditions.

FIELD-EFFECT TRANSISTOR (FET) A type of transistor that uses an induced electric field within its structure to

control current.


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Glossary 17- 9


FILTERA type of circuit that passes certain frequencies and rejects all others.

FREE ELECTRONA valence electron that has broken away from its parent atom and is free to

move from atom to atom within the atomic structure of a material.

FREQUENCYA measure of the rate of change of a periodic function, the number of cycles

completed in 1 s. The unit of frequency is the hertz.

FREQUENCY RESPONSEIn electrical circuits, the variation in the output voltage (or current) over a

specified range of frequencies.

FULL-WAVE RECTIFIERA circuit that converts an alternating sine wave into a pulsating dc consisting of

both halves of a sine wave for each input cycle.

FUNDAMENTAL FREQUENCYThe repetition rate of a waveform.

FUSEA protective device that burns open when there is excessive current in a circuit.

GAINThe amount by which an electrical signal is increased or decreased; the ratio of

output to input; the amount of amplification.

GATEOne of the three terminals of an FET.

GENERATORAn energy source that produces electrical signals.

GERMANIUMA semiconductive material.

GROUNDIn electronic circuits, the common or reference point.


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17-10 Glossary


HALF-POWER FREQUENCYThe frequency at which the output of a filter is 70.7% of maximum.

HALF-WAVE RECTIFIERA circuit that converts an alternating sine wave into a pulsating dc consisting of

one-half of a sine wave for each input cycle.

HARMONICSThe frequencies contained in a composite waveform, which are integer

multiples of the repetition frequency (fundamental).

HENRY (H)The unit of inductance.

HERTZ (Hz)The unit of frequency and hence 1Hz equals one cycle per second.

HIGH-PASS FILTERA certain type of filter whereby higher frequencies are passed and lower

frequencies are rejected.

HOLEThe absence of an electron in the valence band of an atom.

HYSTERESISA characteristic of a magnetic material whereby a change in magnetization lags

the application of a magnetic force.

IMPEDANCE (Z)The total opposition to sinusoidal current expressed in ohms.

IMPEDANCE MATCHINGA technique used to match a load resistance to an internal source resistance in

order to achieve a maximum transfer of power.

INDUCED VOLTAGEVoltage produced as a result of a changing magnetic field.

INDUCTANCE (L)

The property of an inductor that produces an opposition to any change incurrent.

INDUCTIVE REACTANCE (XL)The opposition of an inductor to sinusoidal current. The unit is the ohm.

INDUCTIVE SUSCEPTANCE (BL)The reciprocal of inductive reactance and the unit is siemens


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Glossary 17- 11


INDUCTORAn electrical device formed by a wire wound in a coil around a core having theproperty of inductance and the capability to store energy in its electromagneticfield; also known as a coil or a choke.

INSTANTANEOUS VALUEThe voltage or current value of a waveform at a given instant in time.

INSULATORA material that does not allow current under normal conditions.

INTEGRATORA circuit that produces an output that approaches the mathematical integral of

the input.

INTERFACETo make the output of one type of circuit compatible with the input of another so

that they can operate properly together.

INTRINSIC SEMICONDUCTORA pure semiconductive material with relatively few free electrons.

IONAn atom that has gained or lost a valence electron resulting in a net positive or

negative charge.

IONIZATIONThe removal or addition of an electron from or to a neutral atom so that the

resulting atom (called an ion) has a net positive or negative charge.

JOULE (J)

The unit of energy.

JUNCTIONA point at which two or more components are connected.

JUNCTION FIELD-EFFECT TRANSISTOR (JFET)A type of FET that operates with a reverse-biased junction to control current in

a channel.

KILOWATT-HOUR (kWh)A common unit of energy used mainly by utility companies.

KIRCHHOFFS CURRENT LAWA law stating that the total current into a junction equals the total current out of

the junction.


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17-12 Glossary


KIRCHHOFFS VOLTAGE LAW

A law stating that (1) the sum of the voltage drops around a closed loop equalsthe source voltage or (2) the sum of all the voltages (drops and sources)around a closed loop is zero.

LAGDescribes a condition of the phase or time relationship of waveforms in which

one waveform is behind the other in phase or time.

LEADDescribes a condition of the phase or time relationship of waveforms in which

one waveform is ahead of the other in phase or time; also, a wire or cableconnection to a device or instrument.

LEADING EDGEThe fist step or transition of a pulse.

LENZS LAW

A physical law that states when the current through a coil changes, an inducedvoltage is created in a direction to oppose the change in current. The currentcannot change instantaneously.

LIGHT-EMITTING DIODE (LED)A type of diode that emits light when there is forward current.

LIMITERA circuit that removes part of a waveform above or below a specified level; a

clipper.

LINEARCharacterized by a straight-line relationship.

LINE REGULATIONThe percent change in output voltage for a given change in line (input) voltage.

LOADAn element (resistor or other components) connected across the output

terminals of a circuit that draws current from the circuit.

LOAD REGULATIONThe percent change in output voltage for a given change in load current.

LOW-PASS FILTERA certain type of filter in which lower frequencies are passed and higher

frequencies are rejected.


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Glossary 17- 13


MAGNETIC COUPLINGThe magnetic connection between two coils as a result of the changingmagnetic flux lines of one coil cutting through the second coil.

MAGNETIC FLUXThe lines of force between the north and south poles of a permanent magnet or

an electromagnet.

MAGNETIC FLUX DENSITYThe number of lines of force per unit area perpendicular to a magnetic field.

MAGNETIZING FORCEThe amount of mmf per unit length of magnetic material.

MAGNETOMOTIVE FORCE

The force that produces a magnetic field.

MAGNITUDEThe value of a quantity, such as the number of volts of voltage or the number of

amperes of current.

MAXIMUM POWER TRANSFER THEOREMA theorem that states the maximum power is transferred from a source to a

load when the load resistance equals the internal source resistance.

MOSFETMetal oxide semiconductor field-effect transistor.

MULTIMETER

An instrument that measures voltage, current and resistance.

MUTUAL INDUCTANCE (LM)The inductance beteen two separate coils, such as transformers.

NEGATIVE FEEDBACKThe return of a portion of the output signal to the input such that it is out of

phase with the input signal.

NEUTRONAn atomic particle having no electrical charge.

OHM ( )The unit of resistance.

OHMMETERAn instrument for measuring resistance.


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17-14 Glossary


OHMS LAW

A law stating that current is directly proportional to voltage and inverselyproportional to resistance.

OPEN CIRCUITA circuit in which there is not a complete current path.

OPEN-LOOP GAIN (Aol)The internal voltage gain of an op-amp without feedback.

OPERATIONAL AMPLIFIERA special type of amplifier exhibiting very high open-loop gain, very high input

impedance, very low output impedance, and good rejection of common-modesignals.

OSCILLATORAn electronic circuit consisting of an amplifier and a phase-shift network

connected in a positive feedback loop that produces a time-varying outputsignal using positive feedback.

OSCILLOSCOPEA measurement instrument that displays signal waveforms on a screen.

PARALLELThe relationship in electric circuits in which two or more current paths are

connected between the same two points.

PARALLEL RESONANCEIn a parallel RLC circuit, the condition where the impedance is maximum and

the reactance are equal.

PEAK INVERSE VOLTAGE (PIV)The maximum value of reverse voltage which occurs at the peak of the input

cycle when the diode is reversed-biased.

PEAK VALUEThe voltage or current value of a waveform at its maximum positive or negative

points.

PEAK-TO-PEAK VALUEThe voltage or current value of a waveform measured from its minimum to its

maximum points.PERIOD (T)

The time interval of one complete cycle of a given sine wave or any periodicwaveform.


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Glossary 17- 15


PERIODICCharacterized by a repetition at fixed time intervals.

PERMEABILITYThe measure of ease with which a magnetic field can be established in a

material.

PHASEThe relative displacement of a time-varying waveform in terms of its occurrence

with respect to a reference.

PHASORA representation of a sine wave in terms of both magnitude and phase angle.

PHOTOCONDUCTIVE CELL

A type of variable resistor that is light-sensitive.

PHOTODIODEA diode whose reverse resistance changes with incident light.

PINCH-OFF VOLTAGEThe value of the drain-to-source voltage of an FET at which the drain current

becomes constant when the gate-to-source voltage is zero.

PN JUNCTIONThe boundary between n-type and p-type semiconductive materials.

POLEIn practical terms, a single RC circuit in a filter or amplifier that causes the

response to change at a 20 dB per decade rate above or below a certainfrequency.

POSITIVE FEEDBACKThe return of a portion of the output signal to the input such that it is in phase

with the input signal.

POTENTIOMETERA three-terminal variable resistor.

POWERThe rate of energy usage.

POWER FACTOR

The relationship between volt-amperes and true power or watts. Volt-amperesmultiplied by the power factor equals true power.


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17-16 Glossary


POWER GAINThe ratio of output power to input power; the product of voltage gain and

current gain.

POWER RATINGThe maximum amount of power that a resistor can dissipate without being

damaged by excessive heat buildup.

POWER SUPPLYAn electronic instrument that produces voltage, current and power from the ac

power line or batteries in a form suitable for use in powering electronicequipment.

PRIMARY WINDINGThe input winding of a transformer; also called primary.

PROTONA positively charged atomic particle.

PULSEA type of waveform that consists of two equal and opposite steps in voltage or

current separated by a time interval.

PULSE RESPONSEThe reaction of a circuit to a given input.

PUSH-PULLA type of class B amplifier in which one output transistor conducts for one half-

cycle and the other conducts for the other half-cycle.

Q-POINTThe dc operating (bias) point of an amplifier.

QUALITY FACTOR (Q)The ratio of reactive power to true power in a coil or a resonant circuit.

RAMPA type of waveform characterized by a linear increase or decrease in voltage or

current.

REACTIVE POWERThe rate at which energy is stored and alternately returned to the source by a

capacitor or inductor. The unit is the VAR.

RECOMBINATION The process of a free electron falling into a hole in the valence band of an

atom.


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Glossary 17- 17


RECTIFIERAn electronic circuit that converts ac into pulsating dc; one part of a powersupply.

REFLECTED LOADThe load as it appears to the source in the primary of a transformer.

REFLECTED RESISTANCEThe resistance in the secondary circuit reflected into the primary circuit.

REGULATORAn electronic circuit that maintains an essentially constant output voltage with a

changing input voltage or load.

RELAY

An electromagnetically controlled mechanical device in which electricalcontacts are open or closed by a magnetizing current.

RELUCTANCEThe opposition to the establishment of a magnetic field in a material.

RESISTANCEOpposition to current and its unit is ohm.

RESISTORAn electrical component designed specifically to provide resistance.

RESOLUTIONThe smallest increment of a quantity that a meter can measure.

RESONANT FREQUENCYThe frequency at which a resonant condition occurs in a series or parallel RLC

circuit.

RETENTIVITYThe ability of a material, once magnetized, to maintain a magnetized state

without the presence of a magnetizing force.

REVERSE BREAKDOWNThe condition of a diode in which excessive reverse-bias voltage causes a

rapid buildup of reverse current.

RHEOSTAT

A two terminal variable resistor.RIPPLE VOLTAGE

The small variation in the dc voltage on the output of a filtered rectifier causedby the slight charging and discharging action of the filter capacitor.


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17-18 Glossary


RISE TIMEThe time interval required for a pulse to change from 10% to 90% of its

amplitude.

RISING EDGEThe positive-going transition of a pulse.

ROLL-OFFThe decrease in the response of a filter below or above a critical frequency.

ROOT MEAN SQUARE (rms)The value of a sine wave that indicates its heating effect, also known as the

effective value. It is equal to 0.707 times the peak value.

SATURATIONThe state of a BJT in which the collector current has reached a maximum and

is independent of the base current.

SAWTOOTH WAVEFORMA type of electrical waveform composed of ramps; a special case of a triangular

waveform in which one ramp is much shorter than the other.

SCHEMATICA symbolized diagram of an electrical or electronic circuit.

SECONDARY WINDINGThe output winding of a transformer; also called secondary.

SELECTIVITY A measure of how effectively a filter passes certain frequencies and rejects

others. The narrower the bandwidth, the greater the selectivity.

SEMICONDUCTORA material that has a conductance value between that of a conductor and that

of an insulator. Silicon and germanium are examples.

SENSITIVITY FACTORThe ohms-per-volt rating of a voltmeter.

SERIES In an electrical circuit, a relationship of components in which the components

are connected such as they provide a single current path between two points.

SERIES RESONANCE

In a series RLC circuit, the condition where the impedance is minimum and thereactances are equal.

SHELLAn energy band in which electrons orbit the nucleus of an atom.


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Glossary 17- 19


SHORT CIRCUITA zero or abnormally low resistance between two points; usually an inadvertentcondition.

SILICONa SEMICONDUCTIVE MATERIAL USED IN DIODES AND TRANSISTORS.

Silicon-controlled rectifier (SCR)A device that can be triggered on to conduct current in one direction.

SOLENOIDAn electromagnetically controlled device in which the mechanical movement of

a shaft or plunger is activated by a magnetizing current.

SOURCE

Any device that produces energy, one of the three terminals of FET.

STEADY STATEThe equilibrium condition of a circuit that occurs after an initial transient time.

STEP-DOWN TRANSFORMERA transformer in which the secondary voltage is less than the primary voltage.

STEP-UP VOLTAGE TRANSFORMERA transformer in which the secondary voltage is greater than the primary

voltage.

STOPBANDThe range of frequencies between the upper and lower cutoff points.

SUPERPOSITIONAmethod for analyzing circuits with two or more sources by examining the

effects of each source by itself and then combining the effects.

SWITCHAn electrical or electronic device for opening and closing a current path.

TANK CIRCUITA parallel resonant circuit.

TAPEREDNonlinear, such as tapered potentiometer.

TEMPERATURE COEFFICIENT A constant specifying the amount of change in the value of a quantity for a

given change in temperature.


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17-20 Glossary


TERMINALAn external contact point on an electronic device.

TERMINAL EQUIVALENCYA condition that occurs when two circuits produce the same load voltage and

load current where the same value of load resistance is connected to eithercircuit.

TESLAThe unit of flux density.

THERMISTORA type of variable resistor that is temperature-sensitive.

THEVENINS THEOREM

A circuit theorem that provides for reducing any resistive circuit to a singleequivalent voltage source in series with an equivalent resistance.

THYRISTORA class of four-layer semiconductive devices.

TRAILING EDGEThe second step or transition of a pulse.

TRANSFORMERA device formed by two or more windings and are magnetically coupled to each

other and providing a transfer of power electromagnetically from one winding toanother.

TRANSIENTA temporary passing conductor in a circuit; a sudden or temporary change in

circuit conditions.

TRANSISTORA semiconductive device used for amplification and switching applications in

electronic circuits.

TRIANGULAR WAVEA type of electrical waveform that consists of two ramps.

TRIGGERThe activating mechanism of some electronic devices or instruments.

TRIMMER

Small variable capacitor.

TURNS RATIOThe ratio of turns in the secondary winding to turns in the primary winding.


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Glossary 17- 21


UNIJUNCTION TRANSISTOR (UJT)A type of transistor consisting of an emitter and two bases.

UNITY GAINA gain of 1.

VALENCERelated to the outer shell or orbit of an atom.

VALENCE ELCTRONAn electron that is present in the outermost shell of an atom.

VARACTORA diode that is used as a voltage-variable capacitor.

VOLTThe unit of voltage or electromotive force.

VOLTAGEThe amount of energy available to move a certain number of electrons from

one point to another in an electric circuit.

VOLTAGE DROPThe potential difference in voltage between two points when there is a drop in

energy level due to resistance.

VOLTAGE GAINThe ratio of output voltage to input voltage.

VOLTAGE REGULATIONThe process of maintaining an essentially constant output voltage over

variations in input voltage or load.

VOLTAGE-AMPERE REACTIVE (VAR)The unit of reactive power.

VOLTMETERAn instrument used to measure voltage.

WATT (W)The unit of power.

WATTS LAW

A law that states the relationship of power to current, voltage, and resistance.

WAVEFORMThe pattern of variations of a voltage or current showing how the quantity

changes with time.


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17-22 Glossary


WEBERThe unit of magnetic flux.

WINDINGThe loops or turns of wire in an inductor.

WIPERThe sliding contact in a potentiometer.

ZENER DIODEA type of diode that operates in reverse breakdown (called zener breakdown) to

provide voltage regulation.

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