18WuD2x

General Packet Radio Service • geometric progression 313
General Packet Radio Service A form of packet
radio especially designed for mobile use. Subscribers
pay for the volume of data they send and
receive, rather than for the time they spend accessing
the network. This optimizes the efficiency
of the network, both from an engineering standpoint
and a financial standpoint. See PACKET
COMMUNICATIONS.
general-purpose bridge See UNIVERSAL BRIDGE.
general-purpose component A component designed
or used for a wide range of applications.
For example, a general-purpose germanium
diode is useful as a detector, mixer, limiter, clipper,
meter rectifier, automatic-gain-control (AGC)
rectifier, and curve changer.
general-purpose computer A computer that can
be used in a number of applications for which it
was not specifically designed.
general-purpose diode A small-signal semiconductor
diode that is useful for a variety of applications,
such as detection, light-duty
rectification, limiting, logic switching, etc.
general-purpose function generator A nonspecialized
function generator that is capable of generating
a variety of different waveforms.
general-purpose program A program for the solution
of a class of problems or for a specific problem,
according to certain parametric values. Also
called general routine.
general-purpose relay Any relay that can be used
in various situations, such as for switching alternating
or direct currents.
general-purpose tester An instrument, such as a
voltohm-milliammeter, that offers several test capabilities.
general-purpose transistor A transistor that can
be used in several applications, such as audio
amplification, detection, and oscillation.
general service code See CONTINENTAL CODE.
generate 1. To produce a signal or carrier wave.
2. To convert some non-electrical form of energy
(usually mechanical) into electrical energy.
3. To develop subroutines from parameters applied
to skeletal coding. 4. To use a program
generator to produce a specialized version of a
general-purpose program.
generated address An address developed by program
instructions for later use by that program.
generated noise 1. Electrical noise caused by battery
action (i.e., between dissimilar metals) in a
component, such as in a potentiometer. 2. Electrical
noise caused by small output variations of
generating devices (rotating machines, vibrators,
etc.). Also called generator noise.
generating magnetometer See EARTH INDUC-
TOR.
generating station An electric power station.
generating voltmeter An instrument based on a
rapidly spinning variable capacitor. A directcurrent
(dc) voltage applied to the capacitor is
converted into an alternating current (ac) by the
varying capacitance; the ac is proportional to the
voltage.
generation 1. The production of a signal or carrier
wave. 2. The conversion of some non-electrical
form of energy (usually mechanical) into electrical
energy. 3. The number of recording steps between
a master recording and a copy. 4. A copy of
data in any form (e.g., tape recording, disk file,
and photocopy).
generation number A number that identifies the
age of a file; it is included in the file label on the
disk or tape containing the file.
generator 1. Symbol, G. Any signal source. 2. A
rotating machine for producing electricity. 3. An
electronic device for converting direct current into
alternating current of a specific frequency and
waveshape. 4. In computer operation, a routine
(akin to a compiler) that will produce a program
to perform a specific version of some general operation
by implementing skeletal coding, according
to specific parameters (e.g., sort generator).
generator efficiency The ratio of consumed power
to delivered power in a generator. It is usually expressed
as a percentage.
generator noise Electrical noise caused by a rotating
generator. Also see GENERATED NOISE, 2.
generator-type microphone A microphone that
produces an output voltage without the need for
a supply voltage. Examples: ceramic, crystal, dynamic,
electret, and velocity types.
generator-type transducer A transducer that converts
mechanical motion into an electrical signal
of a proportional voltage. In such a transducer, an
armature or conductor moves in a magnetic field.
generic A form of software collection. Several
specialized software packages can be derived
from the generic collection, for use in different
systems.
geodesic 1. On a surface, the shortest path between
two points. 2. The shortest path between two geographical
locations, measured over the surface of
the earth. Also called geodetic and great circle.
geodesy The branch of applied mathematics concerned
with the precise dimensions of the earth.
geodetic system The application of a computer to
seismographic studies for the purpose of reducing
drilling and mining costs.
geomagnetic field See EARTH’S MAGNETIC
FIELD.
geomagnetism The earth’s magnetism. Also see
EARTH’S MAGNETIC FIELD.
geometric capacitance The ratio of the free
charge of a capacitor to the voltage across its
terminals.
geometric mean The nth root of the product of n
quantities.
geometric progression A mathematical sequence
in which each term after the first is obtained by
multiplying the preceding one by a constant
quantity (e.g., 1, 2, 4, 8, 16, 32, 64, . . .). Also
called geometric sequence.