18WuD2x

158 crystal tetrode • current antinode
crystal tetrode A transistor having four elements:
emitter, collector, and two bases.
crystal transducer A transducer using a piezoelectric
crystal as the sensitive element. Examples:
crystal earphone, crystal loudspeaker,
crystal microphone, and crystal pickup.
crystal triode See TRANSISTOR.
Cs Symbol for CESIUM.
CS Abbreviation of COMPLEMENTARY SYMME-
TRY. Also COS.
C S 1. Symbol for standard capacitance. 2. Symbol
for source capacitance.
csc Abbreviation of COSECANT.
C scan See C DISPLAY.
csch Abbreviation of HYPERBOLIC COSECANT.
C scope A cathode-ray tube used in radar to provide
a C DISPLAY.
CT-cut crystal A piezoelectric plate cut from a
quartz crystal at an angle of rotation around the
X-axis of +38°. Such a plate has a zero temperature
coefficient of frequency at 25°C. Also see
CRYSTAL AXES and CRYSTAL CUTS.
CTL Abbreviation of complementary-transistor
logic.
Cu Symbol for COPPER.
cube 1. A regular polyhedron with six identical
square faces and eight vertices. At each vertex,
three edges converge at mutual right angles. 2.
The third power of a number; thus the cube of n
is written n 3 .
cube tap An electrical adapter, in which a set of
male prongs and three sets of female contacts are
on the sides of a molded cube. Allows three appliances
to be used with a single electrical socket.
To wall
outlet
cube tap
To
appliances
cubical antenna An antenna in which the elements
form the outline of a geometric cube or
rectangular prism. The most common example is
the QUAD ANTENNA.
cubical quad antenna See QUAD ANTENNA.
cubic equation A polynomial equation of the third
degree. Its general form is ax 3 + bx 2 + cx + d = 0.
cue A condition or signal that alerts an operator,
circuit or system to act in a specific manner.
cue circuit A device for transmitting cues used in
program control.
cueing receiver 1. A (usually miniature) radio receiver
used to pick up cues. Example: a receiver
carried by a technician, actor, or lecturer. 2. A receiver
or other pickup circuit that receives a cuing
pulse, which it uses to set another circuit.
cu ft Abbreviation of cubic foot or cubic feet.
cu in Abbreviation of cubic inch or cubic inches.
cumulative error In a sum or other final value, the
total error that has accumulated from the individual
errors in the terms. Also called systematic
error.
cup core A coil core that also forms a magnetic
shield around the coil.
cuprous-oxide rectifier See COPPER-OXIDE
RECTIFIER.
cur Abbreviation of CURRENT.
curie Abbreviation Ci. A unit of radioactivity; 1
curie is the amount of radiation from (or in equilibrium
with) 1 gram of radium. Also equivalent to
3.7 × 10 10 atomic breakdowns per second.
Curie point 1. The temperature above which a ferromagnetic
material loses its magnetism or becomes
paramagnetic. 2. The temperature at
which the ferroelectric properties of a substance
disappear.
curie temperature As a magnetized substance is
heated, the lowest temperature at which magnetization
is lost. It is generally measured in degrees
Celsius or degrees Kelvin. For iron, this temperature
is 760 degrees Celsius; for nickel, it is 356
degrees Celsius.
Curie’s law For a paramagnetic substance, the ratio
of the magnetization to the magnetizing force
is inversely proportional to the absolute temperature.
Curie-Weiss law Above the Curie point, the susceptibility
of a paramagnetic material varies inversely
as the excess of temperature above the
Curie point increases. This law is invalid for applications
at or below the Curie point.
curium Symbol, Cm. A radioactive metallic element
produced artificially. Atomic number, 96.
Atomic weight, 247.
current Symbol, I or i. The movement of charge
carriers, such as electrons, holes, or ions. Also
see AMPERE.
current amplification 1. An electronic process
in which the instantaneous, average, or peak
magnitude of a current is increased. 2. The extent
to which a current increases in a circuit;
the ratio (always greater than one) of output
current to input current, I out /I in . Also called current
gain.
current amplifier An amplifier operated primarily
to increase a signal current. Compare POWER
AMPLIFIER and VOLTAGE AMPLIFIER.
current antinode See CURRENT LOOP.