magnet - Body that can be used to attract or repel magnetic materials.
magnetic circuit breaker - Circuit breaker that is tripped or activated by use of an electromagnet.
magnetic coil - Spiral of a conductor which is called an electromagnet.
magnetic core - Material that exists in the center of the magnetic coil to either physically support the windings (non-magnetic material) or to concentrate the magnetic flux (magnetic material).
magnetic field - Magnetic lines of force traveling from the north pole to the south pole of a magnet.
magnetic flux - The magnetic lines of force produced by a magnet.
magnetic leakage - The passage of magnetic flux outside the path along which it can do useful work.
magnetic poles - Points of a magnet from which magnetic lines of force leave (north pole) and arrive (south pole).
magnetism - Property of some materials to attract or repel others.
magnetizing force - Also called magnetic field strength. It is the
magneto motive force per unit length at any given point in a magnetic circuit.
magneto motive force - Force that produces a magnetic field.
majority carriers - The conduction band electrons in an n-type material and the valence band holes in a p-type material. Produced by pentavalent impurities in n-type material and trivalent impurities in p-type material.
matched impedance - Condition that occurs when the output impedance of a source is equal to the input impedance of a load.
matching - Connection of two components or circuits so that maximum power is transferred between the two.
maximum power transfer - A theorem that states that maximum power will be transferred from source to load when input impedance of the load equals the output impedance of the source.
Maxwell - Unit of magnetic flux. One maxwell equals one magnetic line of force.
mercury cell - Primary cell using a mercuric oxide cathode, a zinc anode and a potassium hydroxide electrolyte.
metal film resistor - A resistor in which a film of metal oxide or alloy is deposited on an insulating substrate.
metal oxide field effect transistor - (MOSFET) A field effect transistor in which the insulating layer
between the gate electrode and the channel is a metal oxide layer.
metal oxide resistor - A metal film resistor in which an oxide of metal (such as tin) is deposited as a film onto the substrate.
meter - Any electrical or electronic measuring device. In the metric system, it is the unit of length equal to 39.37 inches.
meter FSD current - Value of meter current needed to cause the needle to deflect to its maximum position (full scale deflection).
meter resistance - DC resistance of the meter's armature coil.
mica capacitor - Capacitor using mica as the dielectric.
microphone - Electro acoustic transducer that converts sound energy into electric energy.
microwave - Band of very short wavelength radio waves within the UHF, SHF and EHF bands.
mid-band gain - Gain of an amplifier operating within its bandwidth.
mid-point bias - An amplifier biased at the center of its DC load line.
mil - One thousandth of an inch (0.001 in.)
Miller's theorem - A theorem that allows you to represent a feedback capacitor as equivalent input and output shunt capacitors.
minority carriers - The conduction band holes in n-type material and valence band electrons in p-type material. Most minority carriers are produced by temperature rather than by doping with impurities.
mismatch - Term used to describe a difference between the output impedance of a source and the input impedance of a load. A mismatch prevents the maximum transfer of power from source to load.
modulation - Process by which an information signal (audio for example) is used to modify some characteristic of a higher frequency wave known as a carrier (radio for example).
monostable multivibrator - A multivibrator with one stable output state. When triggered, the circuit output will switch to the unstable state for a predetermined period of time and then return to the stable state. A timer.
molecule - Smallest particle of a compound that still retains its characteristics.
MOSFET - Abbreviation for "metal oxide field effect transistor" also known as an "insulated gate field effect transistor). A field effect transistor in which the insulating layer between the gate electrode and the channel is a metal oxide layer.
moving coil microphone - Microphone that uses a moving coil within a fixed magnetic field. Dynamic microphone.
moving coil pick-up - Dynamic phonograph pick-up in which the stylus causes a coil to move within a fixed magnetic field.
moving coil loudspeaker - Loudspeaker that uses a moving "voice coil" placed within a fixed magnetic field. Audio frequency current in the voice coil causes movement which is mechanically transferred to the speaker cone. Also known as a dynamic loudspeaker.
multimeter - Electronic test equipment that can perform multiple tasks. Typically one capable of measuring voltage, current and resistance. More sophisticated modern digital multimeters also measure capacitance, inductance, current gain of transistors and/or anything else that can be measured electronically.
multiplier resistor - Resistor connected in series with a moving coil meter movement to extend the voltage ranges.
multi segmant display - Device made of several light emitting diodes arranged in a numeric or alphanumeric pattern. By lighting selected segments numeric or alphabet characters can be displayed.
multivibrator - A class of circuits designed to produce square waves or pulses. Astable multivibrators produce continuous pulses without an external stimulus or trigger. Monostable multivibrators produce a single pulse for some predetermined period of time only when triggered. Bistable multivibrators produce a DC output which is stable in either one of two states. Either high or low. An external stimulus or trigger is required for the bistable circuit to change states, either high to low or low to high.
mutual inductance - Ability of one inductor's lines of force to link with another inductor.