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
magnetomotive force per unit
length at any given point in a
magnetic circuit.
magnetomotive 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 betwen 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
Electroacoustic transducer that
converts sound energy into
electric energy.
microwave
Band of very short wavelength
radio waves within the UHF, SHF
and EHF bands.
midband 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.
multisegmant 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.
