Laminated form in the shape of
the letter "E", onto which
inductors and transformers are
wound.
eddy currents
Currents induced into a
conducting core due to the
changing magnetic field. Eddy
currents produce heat which is a
loss of power and lowers the
efficiency of an inductor.
efficiency
The amount of power delivered to
the load of an amplifier as a
percentage of the power required
from the power supply.
electric charge
Electric energy stored on the
surface of a material. Also
known as a static charge.
electric field
A field or force that exists in
the space between two different
potentials or voltages. Also
known as an electrostatic field.
electricity
Science states that certain
particles possess a force field
or charge. The charge possessed
by an electron is negative while
the charge possessed by a proton
is positive. Electricity can be
divided into two groups, static
and dynamic. Static electricity
deals with charges at rest and
dynamic electricity deals with
charges in motion.
electric polarization
A displacement of bound charges
in a dielectric when placed in
an electric field.
electro acoustic
transducer
Device that produces an energy
transfer from electric to
acoustic (sound) or from
acoustic to electric. Examples
include a microphone, earphones
and loudspeakers.
electroluminescence
Conversion of electrical energy
into light energy.
electrolyte
Electrically conducting liquid
(wet) or paste (dry)
electrolytic capacitor
A capacitor having an
electrolyte between the two
plates. A thin layer of oxide is
deposited on only the positive
plate. The oxide acts as the
dielectric for the capacitor.
Electrolytic capacitors are
polarized and so must be
connected in correct polarity to
prevent breakdown.
electromagnet
A coil of wire usually wound on
a soft iron or steel core. When
current is passed through the
coil a magnetic field is
generated. The core provides an
easy path for the magnetic lines
of force. This concentrates the
field in the core.
electromagnetic
communication
Use of an electromagnetic wave
to pass information between two
points. Also called wireless
communication.
electromagnetic induction
Voltage produced in a coil due
to relative motion between the
coil and magnetic lines of
force.
electromagnetic spectrum
List or diagram showing the
range of electromagnetic
radiation.
electromagnetic wave
Wave that consists of both
electric and magnetic variation.
electromagnetism
Relates to the magnetic field
generated around a conductor
when current is passed through
it.
electromechanical
transducer
Device that transforms
electrical energy into
mechanical energy (electric
motor) or mechanical energy into
electrical energy (generator).
electromotive force
(emf) Force that causes the
motion of electrons due to
potential difference between two
points. (voltage)
electron
Smallest sub atomic particle of
negative charge that orbits the
nucleus of an atom.
electron flow
Electrical current produced by
the movement of free electrons
towards a positive terminal.
electrostatic
Related to static electric
charge.
electrostatic field
Force field produced by static
electrical charges.
emitter
The semiconductor region from
which charge carriers are
injected into the base of a
bipolar junction transistor.
emitter feedback
Coupling from the emitter output
to the base input of a bipolar
junction transistor.
emitter follower
A common collector amplifier.
Has a high current gain, high
input impedance and low output
impedance.
energized
Being electrically connected to
a voltage source so the device
is activated.
energy
Capacity to do work.
engineering notation
A floating point system in which
numbers are expressed as
products consisting of a number
greater than one multiplied by
an appropriate power of ten that
is some multiple of three.
enhancement-mode MOSFET
A field effect transistor in
which there are no charge
carriers in the channel when the
gate source voltage is zero.
equivalent resistance
Total resistance of all the
individual resistances in a
circuit.
