18WuD2x

236 electric rings • electroballistics
electric rings Colored rings formed on a plate by
the electrolytic deposition of substances, such as
copper and some peroxides.
electric screen See ELECTROSTATIC SCREEN.
electric shield See ELECTROSTATIC SCREEN.
electric shock A physiological reaction caused by
the passage of electric current through living tissue.
When slight, it is characterized by tingling
sensations and involuntary contractions of the
muscles; a severe shock can cause paralysis, unconsciousness,
heart fibrillation, and/or burns. If
heart fibrillation occurs or if burns are severe,
death can result.
electric spark A momentary, luminous discharge
of electricity in the space between two electrodes.
Compare ARC, 1.
electric steel Steel that has been processed in an
electric furnace.
electric strain See DIELECTRIC STRAIN.
electric strain gauge A device for detecting the
strain that a certain stress produces in a body.
Typically, such a gauge consists of one or more
fine insulated wires cemented to the surface under
test. As the surface becomes strained, the
wire stretches, undergoing a change in electrical
resistance that is proportional to the change in
strain.
electric strength See DIELECTRIC STRENGTH.
electric stress See DIELECTRIC STRESS.
electric stroboscope See ELECTRONIC STROBO-
SCOPE.
electric surface density The ratio of the electric
charge on a surface to the area of the surface.
Compare ELECTRIC VOLUME DENSITY.
electric tachometer See ELECTRONIC TACHO-
METER.
electric telemeter A device that sends metered
data over a wire transmission line to a remote
point for monitoring.
electric thermometer See ELECTRONIC THER-
MOMETER.
electric transcription See ELECTRICAL TRAN-
SCRIPTION.
electric transducer A transducer that responds to
non-electric energy, then delivers a proportional
electric current or voltage to another circuit.
electric tuning A means of adjusting the frequency
of a receiver, transmitter, transceiver, or
oscillator, without the use of mechanical devices.
An example is the use of a varactor diode, whose
capacitance varies with voltage.
electric utilities The power companies that supply
electric current for industrial and consumer
use.
electric vane A small demonstration device consisting
of a rotor having several spokes terminating
in points. The rotor is mounted on a pivot
bearing and, when it is connected to a source of
high voltage, spins from the force of electricity
escaping from the points into the surrounding
air.
Variable
tuning
voltage
Varactor
electric tuning
Tuned circuit
To
osc.
electric vector In an electromagnetic field, the
vector representing the electric component. It is
perpendicular to the magnetic vector.
electric volume density The ratio of the electric
charge in a space to the volume of the space.
Compare ELECTRIC SURFACE DENSITY.
electric watch A small timepiece driven by a tiny,
self-contained electrochemical cell that drives an
electrical escapement or other stepping mechanism.
Compare ELECTRONIC WATCH.
electric wave See ELECTROMAGNETIC WAVES.
electric-wave filter A circuit or device for separating
signals of one frequency from those of other
frequencies.
electric whirl See ELECTRIC VANE.
electric wind 1. Air currents set up by electrons
escaping from the sharp point of a high-voltage
electrode. 2. The outward-rushing plasma (solar
wind) ejected by the sun and traveling through
space.
electrification 1. Generating an electric charge in
a body, as in charging a glass rod by rubbing it
with a silk cloth. 2. Providing electric service (e.g.,
RURAL ELECTRIFICATION). 3. The conversion of
a system from purely mechanical to electrical or
electromechanical.
electroacoustic Pertaining to devices and systems
that exhibit both electrical and acoustic effects.
For example, speakers and microphones are electroacoustic
devices.
electroacoustic device A device that transfers energy
by converting it from electrical to acoustic
form or vice-versa.
electroacoustic transducer A transducer that
converts sound vibrations into electrical pulsations
or, conversely, one that converts electricity
into sound.
electroanalysis Chemical analysis performed by
electrolytic methods.
electroanesthesia Anesthesia produced by an
electric current going through some part of the
body.
electroballistics A branch of physics concerned
with the electrical or electronic measurement of
the velocities and trajectories of projectiles.