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zero voltage See ZERO POTENTIAL.
zero voltage coefficient A voltage coefficient hav-
VTVM ing the value of zero (i.e., one that indicates there
circuit is no voltage-dependent drift of a given quantity).
zero-zero The atmospheric condition in which the
ceiling and visibility both are zero (i.e., extremely
dense fog).
zero set, 2
770 Z gain • Z meter

Z gain The gain (or gain control) of the intensity zinc cadmium sulfide phosphor Either of two
channel of an oscilloscope. Compare X GAIN and similar substances used as a phosphor coating
Y GAIN. for cathode-ray-tube screens. One form glows
zig The short, straight deflection of a point or par- blue; the other form glows red.
ticle, or of a wave along a jagged path in a direc- zinc“carbon cell A common non-rechargeable
tion opposite that of ZAG; a component of electrochemical cell. Produces approximately
ZIGZAG DEFLECTION. 1.5 volts under no-load conditions. Zinc forms
zigzag deflection Deflection of a particle, point, or the outer case or shell, and is the negative elec-
object in a path that contains side-to-side mo- trode. A carbon rod serves as the positive elec-
tion, as well as forward motion. Also see ZAG and trode. The electrolyte is a paste of manganese
ZIG. dioxide and carbon. The cell is inexpensive, and
zigzag rectifier A special version of the three- is commercially available in various sizes. The
phase star (three-phase, half-wave) rectifier cir- shelf life is fairly long. Cells of this type work well
cuit. Direct-current (dc) saturation of the at moderate temperatures, and in applications
transformer secondary is avoided by winding half where the current drain is moderate to high.
the turns of each secondary on a separate core They function poorly at low temperatures. Com-
(i.e., each core carries two half-windings). The op- pare ALKALINE CELL.
posing flux resulting from different phases in the zinc germanate phosphor A substance used as a
half-windings causes cancellation of the dc com- phosphor coating for cathode-ray-tube screens. It
ponent of flux in each core. glows yellow-green.
zigzag reflections Multihop reflections of waves zinc magnesium fluoride phosphor A substance
along a zigzag path, resulting from repeated re- used as a phosphor coating for cathode-ray-tube
flections within the ionosphere. screens. It glows orange.
zinc Symbol, Zn. A metallic element. Atomic num- zincolysis Electrolysis in a cell having a zinc
ber, 30. Atomic weight, 65.39. It is used as the anode.
negative-electrode material in dry cells and as a zinc orthoscilicate phosphor Also called Willemite.
protective coating for some metals used in elec- A substance used as a phosphor coating for
tronics. cathode-ray-tube screens. It glows yellow-green.
zinc oxide A substance used as a phosphor coat-
ing for cathode-ray-tube screens. It glows blue-
green. It is also used in the manufacture of
certain electronic components, such as resistors.
F zinc-oxide resistor A voltage-dependent resistor
dc Output whose active ingredient is zinc oxide.
A zinc silicate phosphor A substance used as a
E phosphor coating for cathode-ray-tube screens. It
glows blue.
zinc standard cell A standard cell using zinc and
mercury electrodes, and a mercurous sulfate ex-
C citant and depolarizer. Produces 1.4322 volts at
15°C. Also called Clark cell. Compare WESTON
zinc sulfide phosphor A substance used as a
phosphor coating for cathode-ray-tube screens.
Glows blue-green or yellow-green.
ZIP Abbreviation of zinc-impurity photodetector.
zigzag rectifier zip cord A simple two-conductor, flexible power
zirconia Preparations of zirconium (especially
zinc aluminate phosphor Either of two similar
Zr02), valued for their high-temperature dielectric
substances used as a phosphor coating for
cathode-ray tube screens. One form glows blue;
zirconium Symbol, Zr. A metallic element. Atomic
the other form glows red.
number, 40. Atomic weight, 91.22.
zinc beryllium silicate phosphor A substance
Z marker A vertically radiating marker beacon
used as a phosphor coating for cathode-ray-tube
defining the zone above a radio-range station.
screens. It glows yellow.
Z meter A device for measuring impedances. In-
zinc beryllium zirconium silicate phosphor A
struments of this kind take four principal forms:
substance used as a phosphor coating for cath-
(1) a direct-reading meter resembling an ohmme-
ode-ray-tube screens. It glows white.
ter; (2) an adjustable circuit manipulated some-
zinc borate phosphor A substance used as a
what like a bridge and that compares an
phosphor coating for cathode-ray-tube screens. It
unknown impedance with a standard resistance;
glows yellow-orange.
Z meter • zwitterion

(3) an impedance bridge for evaluating the reac- which a molten zone in an ingot of the material
tive and resistive components of an unknown moves along the length of the ingot, dissolving
impedance; (4) a section of transmission line impurities as it travels, eventually depositing
used with a signal source and voltmeter for mea- them at the end of the ingot, which is sawed off.
suring impedance in terms of a standard resistor This concentrated and segregated melting is ac-
and/or standing waves. complished by means of radio-frequency heating.
ZMODEM In data communications, an error-cor- zone time In a given time zone, standard time in
rection mode similar to XMODEM, except that terms of the number of hours that must be added
when an error is found during transmission of a to local time to equal the time at the zero (Green-
block of data, the source retransmits only that wich) meridian.
portion of the block following the error. This im- zoning 1. A method of fabricating a microwave
proves data transmission speed because, when reflector in concentric, flat regions, producing
an error occurs, the number of bytes retransmit- the same practical results as a continuous
ted is generally fewer than the 128K block size paraboloid. 2. In a communications system, the
standard in XMODEM. Compare XMODEM and division of the coverage area into different geo-
YMODEM. graphic regions for a specific purpose.
Zn 1. Symbol for ZINC. 2. Symbol for AZIMUTH. zoom 1. To rapidly change the focal length of a
Z0 Symbol for CHARACTERISTIC IMPEDANCE. television or motion-picture camera lens so that
zone 1. On a magnetic disk, a group of tracks the object seems to advance toward or recede
whose associated transfer rate is not the same as from the viewer, remaining in focus as it does so.
that for the rest of the disk. 2. In computer oper- 2. See ZOOM LENS. 3. To magnify the image in a
ations, the area of a storage medium containing computer graphical user interface. A user can en-
digits. 3. In a computer system, a main memory large a specific portion of the display, at the ex-
area set aside for a particular purpose. 4. In a se- pense of other portions. It is generally measured
curity system, a specified area or region under in percent (e.g., 200% zoom represents a magnifi-
surveillance. cation factor of 2).
zone blanking In a radar system, a method of ex- zoom lens A continuously adjustable lens system
tinguishing the cathode-ray-tube beam during a that allows zoom effects to be obtained with a
portion of the antenna sweep. television or motion-picture camera, or a similar
zone candle power In a given zone, the luminous arrangement for still cameras that obviates the
flux per steradian, emitted by a light source un- need for lens interchange when different focal
der test. lengths are needed. The lens system, which can
zoned circuit In a security system, a circuit in be operated electronically, allows either narrow-
which some areas are protected at all times, while or wide-angle views to be obtained without losing
the protection in other areas can be temporarily focus at any time.
disabled for entry or exit. Z parameters Device or network parameters ex-
zone leveling See ZONE REFINING. pressed as impedances.
zone marker See Z MARKER. ZPI Abbreviation of ZONE-POSITION INDICATOR.
zone melting See ZONE REFINING. Z-plunger In a waveguide, a combination choke
zone of silence The region between alternate re- and bucket plunger for radiation leakage reduc-
flections of a radio wave, in which no signal is de- tion.
tectable. Also called skip zone. Zr Symbol for ZIRCONIUM.
zone plate antenna A rapid-scan radar antenna Z signals A collection of letter groups, each starting
having a reflector composed of confocal parabolas with the letter Z, used for simplified telegraphy
arranged in a circle. and radiotelegraphy by the military services.
zone-position indicator A radar that reveals the Zulu Phonetic alphabet communications code
position of an object to a second radar having a word for the letter Z.
restricted field. Zulu time Greenwich mean time. Also see ZEBRA
zone purification See ZONE REFINING. TIME.
zone refining A method of purifying semiconduc- zwitterion An ion that carries both a positive and
tor materials (such as germanium and silicon) in a negative charge.
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Appendix A
Schematic symbols


Amplifier general

Amplifier, inverting

Amplifier, operational

AND gate

Antenna, balanced

Antenna, general

Antenna, loop

Antenna, loop, multiturn

’ +

Capacitor, feedthrough

Capacitor, fixed

Capacitor, variable

Capacitor, variable, split-rotor

Capacitor, variable, split-stator

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774 Appendix A

Cathode, electron-tube, cold

Cathode, electron-tube, directly heated

Cathode, electron-tube indirectly heated

Cavity resonator

’ +
Cell, electrochemical

Circuit breaker

Coaxial cable

Crystal, piezoelectric

Delay line


Diode, field-effect

Diode, general

Diode, Gunn

Diode, light-emitting

Diode, photosensitive
Schematic symbols

Diode, PIN

Diode, Schottky

Diode, tunnel

Diode, varactor

Diode, zener

Directional coupler

Directional wattmeter

Exclusive-OR gate

Female contact, general

Ferrite bead

Filament, electron-tube



Grid, electron-tube

Ground, chassis
776 Appendix A

Ground, earth


Handset, double

Headset, single

Headset, stereo AM
Inductor, air core

Inductor, air core, bifilar

Inductor, air core, tapped

Inductor, air core, variable

Inductor, iron core

Inductor, iron core, bifilar

Inductor, iron core, tapped

Inductor iron core, variable

Inductor, powdered-iron core

Inductor, powdered-iron core, bifilar

Schematic symbols

Inductor, powdered-iron core, tapped

Inductor, powdered-iron core, variable or

Integrated circuit, general (Design-show)

Jack, coaxial or phono

Jack, phone, two-conductor

Jack, phone, three-conductor

Key, telegraph

Lamp, incandescent

Lamp, neon

Male contact, general

Meter, general


778 Appendix A

Microphone, directional


NAND gate

Negative voltage connection

NOR gate

NOT gate


OR gate

Outlet, two-wire, nonpolarized

Outlet, two-wire, polarized

Outlet, three-wire

Outlet, 234-V

Plate, electron-tube

Plug, two-wire, nonpolarized
Schematic symbols

Plug, two-wire, polarized

Plug, three-wire

Plug, 234-V

Plug, coaxial or phono

Plug, phone, two-conductor

Plug, phone, three-conductor

Positive voltage connection


Probe, radio-frequency

Rectifier, gas-filled

Rectifier, high-vacuum

Rectifier, semiconductor

Rectifier, silicon-controlled
780 Appendix A

Relay, double-pole, double-throw

Relay, double-pole, single-throw

Relay, single-pole, double-throw

Relay, single-pole, single-throw

Resistor, fixed

Resistor, preset

Resistor, tapped



Saturable reactor

Signal generator

Solar battery
’ +
Schematic symbols

Solar cell
’ +

Source, constant-current

+ ’
Source, constant-voltage


Switch, double-pole, double-throw

Switch, double-pole, rotary

Switch, double-pole, single-throw

Switch, momentary-contact

Switch, silicon-controlled

Switch, single-pole, rotary

Switch, single-pole, double-throw

Switch, single-pole, single-throw
782 Appendix A

Terminals, general, balanced

Terminals, general, unbalanced

Test point TP

Thermocouple or

Transformer, air core

Transformer, air core, step-down

Transformer, air core, step-up

Transformer, air core, tapped primary

Transformer, air core, tapped secondary

Transformer, iron core

Transformer, iron core, step-down

Transformer, iron core, step-up

Transformer, iron core, tapped primary

Transformer, iron core, tapped secondary
Schematic symbols

Transformer, powdered-iron core

Transformer, powdered-iron core, step-down

Transformer, powdered-iron core, step-up

Transformer, powdered-iron core, tapped primary

Transformer, powdered-iron core,
tapped secondary

Transistor, bipolar, NPN

Transistor, bipolar, PNP

Transistor, field-effect, N-channel

Transistor, field-effect, P-channel

Transistor, MOS field-effect, N-channel

Transistor, MOS field-effect, P-channel

Transistor, photosensitive, NPN

Transistor, photosensitive, PNP
784 Appendix A

Transistor, photosensitive, field-effect,

Transistor, photosensitive, field-effect,

Transistor, unijunction


Tube, diode

Tube, heptode

Tube, hexode

Tube, pentode

Tube, photosensitive

Tube, tetrode
Schematic symbols

Tube, triode



Waveguide, circular

Waveguide, flexible

Waveguide, rectangular

Waveguide, twisted

Wires, crossing, connected or


Wires, crossing, not connected or

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Appendix B
Tables and data
Conversion between Electrical Systems

cgs cgs
Property mks electromagnetic electrostatic
1011 statfarad
Capacitance 1 farad 10 abfarad 9
109 F 1020 statF
1 abF 9
11 20
10 /9 F 10 /9 abF 1 statF

109 statC
Charge 1 coulomb 0.1 abcoulomb 3
1010 statC
10 C 1 abC 3
10 9/3 C 10
10 /3aC 1 statC

1 coulomb/m3 7
abcoulomb/cm3 103 statcoulomb/cm3
Charge density 10 3
107 C/m3 1 abC/cm3 1010 statCcm3
10 3/3 C/m3 10
/3 aC/cm3 1 statC/cm3
109 statSiemens/cm
Conductivity 1 siemens/m 10 absiemens/cm 9
1011 S/m 1020 statS/cm
1 abS/cm 9
10 9/9 S/m 20
10 /9 abS/cm 1 statS/cm
109 statampere
Current 1 ampere 10 abampere 3
1010 statA
10 a 1 abA 3
10 9/3 a 10
10 /3 abA 1 statA

1 ampere/m2 5
abampere/cm2 105 statampere/cm2
Current density 10 3
105 A/m2 1 abA/cm2 1010 statA/cm2
10 5/3 A/m2 10
/3 aA/cm2 1 statA/cm2

106 abvolt/cm 10 4/3 statvolt/cm
Electric field intensity 1 volt/m
6 10
10 V/m 1 abV/cm 10 /3 statV/cm
104 V/m 1010 aV/cm
3 3 1 statV/cm

108 abvolt 10 2/3 statvolt
Electric potential 1 volt
8 10
10 V 1 abV 10 /3 statV
102 V 1010 aV
3 3 1 statV

1011 statC-cm
Electric dipole moment 1 coulomb-m 10 abC-cm 3
1010 statC-cm
0.1 C-m 1 abC-cm 3
11 10
10 /3 C-m 10 /3 abC-cm 1 statC-cm

Copyright © 2001 by The McGraw-Hill Companies, Inc.
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788 Appendix B

cgs cgs
Property mks electromagnetic electrostatic

107 erg 107 erg
Energy 1 joule
10 J 1e 1e
10 J 1e 1e

105 dyne 105 dyne
Force 1 newton
10 N 1d 1d
10 N 1d 1d

1 Weber/m2 104 gauss (or abtesla) 10 6/3 electrostatic unit
Flux density
Wb/m2 10
10 1G 10 /3 esu
6 2 10
3 10 Wb/m 3 10 G 1 esu

109 abhenry 11
Inductance 1 henry 10 /9 stathenry
9 20
10 H 1 abH 10 /9 statH
11 20
9 10 H 9 10 abH 1 statH
109 statfarad/cm
Inductive capacity 1 farad/m 10 abfarad/cm 9
1011 F/m 1020 statF/cm
1 abF/cm 9
10 9/9 F/m 20
10 /9 abF/cm 1 statF/cm

108 Maxwell 10 2/3 electrostatic unit
Magnetic flux 1 weber
8 10
10 W 1 Mx 10 /3 esu
2 10
3 10 W 3 10 Mx 1 esu

1 ampere-m2 103 abampere-cm2 1013 statampere-cm2
Magnetic dipole moment 3
A-m2 1 abA-cm2 1010 statA-cm2
10 3
/3 A-m2 10
/3 abA-cm2 1 statA-cm2
10 10

107 abhenry/cm 13
Permeability 1 henry/m 10 /9 stathenry/cm
7 20
10 H/m 1 abH/cm 10 /9 statH/cm
1013 H/m 1020 abH/cm
9 9 1 statH/cm

107 erg/s 107 erg/s
Power 1 watt
10 W 1 e/s 1e/s
10 W 1 e/s 1e/s

109 abohm 11
Resistance 1 ohm 10 /9 statohm
9 20
10 ohm 1 abohm 10 /9 statohm
11 20
9 10 ohm 9 10 abohm 1 statohm
Tables and data

Capital Lowercase Name
A alpha
B beta
γ gamma
δ or ‚
∆ delta
E epsilon
Z zeta
H eta
θ or
˜ theta
I iota
K kappa
M mu
N nu
O omicron
P rho
or sigma
T tau
… upsilon
or phi

Mathematical Functions

Signs and symbols

radix (base) point not equal to

• multiplication symbol; logic AND function similar to
infinity less than
plus; positive; logic OR function not less than
minus; negative much less than
plus or minus; positive or negative greater than
minus or plus; negative or positive not greater than
times much greater than
divided by equal to or less than

divided by (expressive of a ratio) equal to or greater than
equal to proportional to; varies directly as
or ’
identical to; is defined by approaches
or approximately equal to, congruent to is to; proportional to
approximately equal to therefore
790 Appendix B

@ at the rate of; at cost of x average value of x; x not
e natural number = 2.71828 f(x) or F(x) function of x

pi 3.14159 . . . i 1

() parentheses (use to enclose a group of terms)
[] brackets (use to enclose a group of terms that j operator, equal to 1
includes one or more groups in parentheses) increment of x
{} braces (use to enclose a group of terms that
includes one or more groups in brackets. dx differential of x
∠ ‚x
angle partial differential of x

° degrees (arc or temperature)
′ minutes; prime change in x with respect to y
′′ seconds; double prime
 parallel to derivative of x with respect to y
⊥ perpendicular to
... and beyond (x) derivative of x with respect to y
(del or nabla) vector differential operator dyx derivative of x with respect to y
partial derivative of x with respect to y

x y x added to y; x OR y summation
x y y subtracted from x summation between limits (from a to b)
x y, x y, multiplied by y; x AND y
or xy product
x y x divided by y product between limits (from a to b )
x/y or x divided by y integral
1/x reciprocal of x integral between limits (from a to b)

xn x raised to the indicated power of n x dy integral of x with respect to y
x indicated root n of x |a evaluated at a

x:y x is to y evaluated between limits (from a to b)

|x| absolute value of x, magnitude of x n! factorial of n

X, X, or X vector X
Tables and data

Prefix Quantity Symbol

10 18
atto- a
10 15
femto- f
10 12
pico- p
10 9
nano- n
10 6
10 3
milli- m
10 2
centi- c
10 1
deci- d
deka- 10 da
hecto- h
kilo- k
mega- M
giga- G
tera- T
peta- P
exa- E

The first three color bands supply the total resistance. The fourth color (if any ) gives the tolerance. Example: A
5,600-ohm resistor would have green (first color, 5), blue (second color, 6) and red

1 2 3 4 body

1 2 3 4

black = 0 black = 0 black = gold 5%
brown = 1 brown = 1 brown = 0 silver 10%
red = 2 red = 2 red = 00 no band 20%
orange = 3 orange = 3 orange = 000
yellow = 4 yellow = 4 yellow = 0000
green = 5 green = 5 green = 00000
blue = 6 blue = 6 blue = 000000
violet = 7 violet = 7 gold = multiply by 0.1
gray = 8 gray = 8 silver = multiply by 0.01
white = 9 white = 9
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Suggested additional

Crowhurst, N. and Gibilisco, S., Mastering Technical Mathematics”2nd Edition. New York: McGraw-Hill,
Dorf, R., Electrical Engineering Handbook”2nd Edition. Boca Raton, FL: CRC Press, 1997.
Gibilisco, S., Electronics Portable Handbook. New York: McGraw-Hill, 1999.
Gibilisco, S., Electronics Formulas Pocket Reference. New York: McGraw-Hill, 1999
Gibilisco, S., Mathematical and Physical Data, Equations, and Rules of Thumb. New York: McGraw-Hill,
Van Valkenburg, M., Reference Data for Engineers: Radio, Electronics, Computer and Communications.
Indianapolis: Howard W. Sams & Co., 1998.
Veley, V., The Benchtop Electronics Reference Manual. New York: McGraw-Hill, 1994.

Copyright © 2001 by The McGraw-Hill Companies, Inc.
Click here for Terms of Use.
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About the author
Stan Gibilisco has authored or coauthored dozens of nonfiction books
about electronics and science. He first attracted attention with Under-
standing Einstein™s Theories of Relativity (TAB Books, 1983). His Encyclo-
pedia of Electronics (TAB Professional and Reference Books, 1985) and
Encyclopedia of Personal Computing (McGraw-Hill, 1996) were annotated
by the American Library Association as among the best reference volumes
published in those years. Stan™s work has gained reading audiences in the
Far East, Europe, and South America.

Copyright © 2001 by The McGraw-Hill Companies, Inc.
Click here for Terms of Use.


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