18WuD2x

macro- • magnetic balance 425
macro- Prefix denoting extremely large. Compare
MICRO-.
macro assembly program An assembly program
whose source statements are translated to several
machine-language instructions.
macroinstruction A source program instruction
that becomes several machine-language instructions
when operated on by a compiler.
macroknowledge In artificial intelligence, knowledge
in the large sense (i.e., knowledge about information).
Example: a set of definitions in an
expert system. Compare MICROKNOWLEDGE.
macroprogram A computer program consisting of
macroinstructions.
macrosonics The theory and applications of highamplitude
sound waves.
madistor A component that produces changes in
current by means of magnetic-field effects. It is
used as an oscillator or amplifier.
MADT Abbreviation of MICROALLOY DIFFUSED
TRANSISTOR.
MAG Abbreviation of MAXIMUM AVAILABLE GAIN.
magamp Acronym for MAGNETIC AMPLIFIER.
magazine A tape or film cartridge.
magenta One of the primary pigments used in
color printers. It has a pinkish-red hue.
magnal CRT base An 11-pin base typical of many
cathode-ray tubes.
magnesium Symbol, Mg. A metallic element.
Atomic number, 12. Atomic weight, 24.305.
magnesium fluoride phosphor A substance used
as a phosphor coating on the screen of a verylong-persistence
cathode-ray tube. The fluorescence
and phosphorescence are orange.
magnesium silicate phosphor A substance used
as a phosphor coating on the screen of a cathoderay
tube. The fluorescence is orange-red.
magnesium tungstate phosphor A substance
used as a phosphor coating on the screen of a
cathode-ray tube. The fluorescence is very light
blue.
magnet A device or body of material that has the
ability to attract to itself pieces of iron and other
magnetic metals, and the ability to attract or repel
other magnets. Also see ELECTROMAGNET,
PERMANENT MAGNET, and TEMPORARY MAG-
NET.
magnet armature See KEEPER.
magnet battery A group of several magnets placed
together in parallel (i.e., with similar poles touching
or resting nearby) to act as a single magnet.
magnet charger A device that produces an intense
magnetic field for restoring weakened magnets or
for making new magnets.
magnetic 1. Pertaining to MAGNETISM. 2. Possessing
MAGNETISM. 3. Capable of being magnetized.
2. See MAGNETIC MATERIAL.
magnetic air-gap A space between two magnetic
poles, either the same (in which case the force is
repulsive) or opposite (in which case the force is
attractive).
magnetic amplifier An iron-core device that uses
the principle of the saturable reactor to obtain
amplification. In its simplest form, it consists of
input and output coils wound on a core of
square-loop magnetic metal. The input coil consists
of two identical windings connected in
series-opposition so that currents in the output
winding cannot induce voltage in the input winding.
The output coil is connected in series with a
load and an alternating-current (ac) supply. A
small ac signal applied to the input winding
causes a large change in the impedance of the
output winding and, therefore, a large change in
the voltage across the load.
ac
power
supply
magnetic amplifier
Load
dc
control-signal
input
magnetic analysis See MASS SPECTROMETER.
magnetic attraction 1. The force that causes a
magnetic pole to draw to itself an opposite magnetic
pole. Thus, a north pole attracts a south
pole, and a south pole attracts a north pole. Compare
MAGNETIC REPULSION. 2. The force that
causes a magnetic pole to draw to itself a piece of
magnetic material, such as iron or steel.
magnetic axis A straight line joining the poles of a
magnet.
magnetic bearing The azimuth, or compass direction,
measured with respect to magnetic north
(the direction of the north geomagnetic pole). It is
usually expressed in degrees and can be read directly
from a compass.
magnetic azimuth An azimuth bearing relative to
magnetic north (the direction of the north geomagnetic
pole).
magnetic balance An instrument for measuring
the force, either attractive or repulsive, between
two objects that are magnetized, or between a