18WuD2x

500 orange peel • orthiconoscope
orange peel On a phonograph disc, a mottled surface
that produces high background noise; so
called from its resemblance to an orange peel.
orbit 1. Also called shell. The median path of an
electron around the nucleus of an atom. 2. The
circular or elliptical path of an artificial satellite
(e.g., a communications satellite) around the
earth. 3. The elliptical path of the moon around
the earth. 4. The elliptical path of the earth or another
planet around the sun. 5. Any closed, usually
circular or elliptical path, that an object
follows around another object.
orbital-beam multiplier tube An electronmultiplying
UHF oscillator or amplifier tube in
which a positively charged electrode focuses
electrons in a circular path.
orbital electron An electron in orbit around the
nucleus of an atom.
orbital period The length of time required by a
satellite to go around a celestial body, usually the
earth. It can vary from about 90 minutes for very
low orbits to months or even years for orbits beyond
that of the moon. The moon’s period is
about a month.
OR circuit Also called inclusive-OR circuit. In digital
systems and other switching circuits, a logic
gate whose output is high (logic 1) when any of
the input signals is high. The output is low (logic
0) only when all of the inputs are low. Compare
AND CIRCUIT.
A
Inputs
B
A
0
0
1
1
B
0
1
0
1
C
0
1
1
1
2-input OR circuit
C
Output
order 1. An instruction to a digital computer.
2. Sequence.
OR element See OR CIRCUIT.
ordered pair A set of two variables or numbers
that can be mapped one-to-one onto a set of
points in a plane. The most familiar example is
(x,y), used to depict the Cartesian (rectangular)
coordinate system on which characteristic curves
and other functions are plotted.
order of interference The position of an interference
fringe that depends on whether the interference
arises from one, two, three, or more
wavelength differences. Generally, the first fringe
results from a difference of one wavelength, the
second fringe from a difference of two wavelengths,
etc. The center fringe indicates that the
two signals are exactly in phase; that is, the difference
is zero wavelengths.
order of logic 1. A mathematical expression for
the complexity of a system of logic. 2. The relative
speed with which logical information is processed
in a system.
order tone A warning signal to receiving operators
in the form of a tone transmitted over a trunk
preceding the transmission of an order.
ordinary ray As a result of the double refraction of
electromagnetic waves, the member of a pair of
rays that follows the usual laws of refraction. Also
see O WAVE. Compare EXTRAORDINARY RAY.
ordinary wave See O WAVE.
ordinate In the rectangular coordinate system, a
point located on the vertical axis.
organ 1. A computer subsystem. 2. An electronic
device used for the purpose of generating music.
organic decay See EXPONENTIAL DECREASE.
organic electricity Electricity in the living tissues
of animals and plants.
organic growth See EXPONENTIAL INCREASE.
organic semiconductor A semiconductor material
consisting of, or combined with, some compound
of carbon.
OR gate See OR CIRCUIT.
orientation 1. The direction or position of an object
in space, expressed in terms of coordinate
values. 2. In a teleprinter, the calibration or
alignment that determines the speed of response
to a received character.
orientation of quartz plates See CRYSTAL AXES
and CRYSTAL CUTS.
orifice An opening or window, such as that in a
loudspeaker enclosure or waveguide, through
which energy is transmitted.
origin
1. The starting point in a coordinate system.
2. Relative to address modification in computer
operations, an address to which a modifier is
added to derive a variable operand address.
original lacquer In disc-recording operations, an
original recording made on a lacquer-surfaced
disc that is subsequently used to make a master.
original master In disk recording, the master disc
produced from a wax or lacquer disc (see ORIGI-
NAL LACQUER) by means of electroforming.
origin distortion The change in the shape of a
wave as it swings through zero (polarity).
OR operation See OR CIRCUIT.
ORS Abbreviation of OMNIDIRECTIONAL RANGE
STATION.
orthicon A television camera tube somewhat similar
to the iconoscope, but which provides internal
amplification of light and, accordingly, can be
used in dimmer places than the iconoscope. Light
amplification is provided by an arrangement similar
to that of a photomultiplier tube.
orthiconoscope See ORTHICON.