Neets Master Glossary

1-42 MAGNET WIRE—Wire coated with an enamel insulation and used in coils, relays, transformers, motor windings, and so forth [4]. MAGNETIC AMPLIFIER—An electromagnetic device that uses one or more saturable reactors to obtain a large power gain. This device is used in servosystems requiring large amounts of power to move heavy loads [8] [15]. MAGNETIC FIELD—(1) The region in which the magnetic forces created by a permanent magnet or by a current-carrying conductor or coil can be detected [1] [2]. (2) The field that is produced when current flows through a conductor or antenna [10] [11]. MAGNETIC INDUCTION—Generating a voltage in a circuit by the creation of relative motion between a magnetic field and the circuit. The relative motion can be the result of physical movement or the rise and fall of a magnetic field created by a changing current [5]. MAGNETIC LINES OF FORCE—Imaginary lines used for convenience to designate the direction in which magnetic forces are acting as a result of magnetomotive force [2]. MAGNETIC MICROPHONE—A microphone in which the sound waves vibrate a moving armature. The armature consists of a coil wound on the armature and located between the pole pieces of a permanent magnet. The armature is mechanically linked to the diaphragm [12]. MAGNETIC POLES—The section of a magnet where the flux lines are concentrated; also where they enter and leave the magnet [1]. MAGNETIC TRIP ELEMENT—A circuit breaker trip element that uses the increasing magnetic attraction of a coil with increased current to open the circuit [3]. MAGNETISM—The property possessed by certain materials by which these materials can exert mechanical force on neighboring masses of magnetic materials and can cause currents to be induced in conducting bodies moving relative to the magnetized bodies [1]. MAGNETRON OSCILLATOR—An electron tube that provides a high power output. Theory of operation is based on interaction of electrons with the crossed electric and magnetic fields in a resonant cavity [18]. MAINTENANCE—Work done to correct, reduce, or counteract wear, failure, and damage to equipment [16]. MAJOR LOBE—The lobe in which the greatest amount of radiation occurs [10]. MAJORITY CARRIERS—The mobile charge carriers (hole or electron) which are predominate in a semiconductor material; for example, electrons in an N-type region [7]. MARCONI ANTENNA—A quarter-wave antenna that is operated with one end grounded and is positioned perpendicular to the earth [10]. MARK—An interval during which a signal is present. Also the presence of an RF signal in cw keying. The key-closed condition (presence of data) in communications systems [12]. MARKING—The state where a circuit is closed and current flows in teletypewriter operation [17]. MASK—A device used to deposit materials on a substrate in the desired pattern [14].